Macromers and compositions for photocuring processes

Abstract

To provide compounds and compositions which are useful in additive printing techniques, particularly additive printing such as stereolithography (SLA) where a macromer is photopolymerized to form a manufactured article.SOLUTION: Representative compounds comprise a polyaxial central core (CC) and 2-4 arms of the formula (A)-(B) or (B)-(A) extending from the central core, where at least one of the arms comprise a light-reactive functional group (Q), and where (A) is the free-radical polymerization product from monomers selected from trimethylene carbonate (T) and ε-caprolactone (C) while (B) is the free-radical polymerization product from monomers selected from glycolide, lactide and p-dioxanone.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62 / 660,146, filed April 19, 2018, which is incorporated herein by reference in its entirety for all purposes. The present invention relates generally to compounds and compositions useful in photocuring processes, such as stereolithography (SLA), in which macromers are photopolymerized to form articles of manufacture, and related methods. [Background technology]

[0002] Stereolithography (SLA) is a relatively well-developed additive printing technique for fabricating three-dimensional (3-D) objects. Stereolithography uses light, such as ultraviolet (UV) or visible light, to photopolymerize liquid materials to create designed structures (e.g., three-dimensional articles) with high accuracy and precision. Thin, successive layers are photocrosslinked with UV or visible light under the direction of, for example, a sliced ​​CAD (computer-aided design) model. SLA uses liquid photocrosslinkable polymer compositions, sometimes commonly referred to as resin or ink formulations. The macroscopic properties and degradation profiles of articles produced by SLA depend in part on the polymer chemistry and processing techniques. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 07-033844 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-246851 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-139542 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides compounds and compositions useful in photocuring processes such as stereolithography (SLA), in which macromers are photopolymerized to form, for example, a solid surface or article of manufacture. All subject matter discussed in the "Background" section is not necessarily prior art and should not be considered prior art merely as a result of the discussion in the "Background" section. Similarly, any recognition of a problem in the prior art discussed in the "Background" section or related to such subject matter should not be treated as prior art unless expressly stated to be prior art. Instead, the discussion of any subject matter in the "Background" section should be treated as part of the inventor's approach to a particular problem and may itself be inventive. [Means for solving the problem]

[0005] Briefly, in one aspect, the present disclosure provides compounds and compositions useful in photocuring processes. Photocuring processes are useful for manufacturing articles such as medical devices and coatings. An exemplary photocuring process is stereolithography (SLA), an additive manufacturing process in which macromers are photopolymerized to form manufactured articles. Another exemplary photocuring process is a coating process, whereby compounds and / or compositions of the present disclosure are disposed on a surface and then cured (i.e., photopolymerized or photocured) with actinic radiation to provide a solid coating on the surface. These photopolymerized / photocured products may be generally referred to herein as articles, coatings, films, materials, etc. Thus, when illustrating the present disclosure by preparing articles, it should be understood that coatings or other materials can be similarly prepared. In one aspect, the articles, coatings, etc. are biodegradable.

[0006] In one aspect, the present disclosure provides biodegradable polymeric materials. The materials can be used to manufacture limited-life articles, such that after a certain period of time, the article formed from the biodegradable material no longer exists. For example, the material can be a coating on a device, such as a medical device, which degrades after a certain period of time. In another example, the material can be used to fabricate a medical device (e.g., a tissue repair mesh), such that after a certain period of time, the article is partially or completely absent and tissue repair is achieved. According to the present disclosure, in one aspect, stereolithography can be used to prepare such materials and articles, for example, using the compounds and compositions disclosed herein. The present disclosure addresses concerns regarding photopolymerized materials, such as SLA-made articles, that come into contact with living organisms, such as concerns regarding the safety and efficacy of the manufactured articles, particularly their biocompatibility and cytotoxicity. In one aspect, disclosed herein are methods and compositions for photopolymerization processes, such as 3D printing, and methods and compositions for making and using such photopolymerized articles. For example, the present disclosure provides a method of photopolymerizing and printing an article, comprising: a) exposing a photopolymerizable composition comprising at least one photopolymerizable macromer component disclosed herein, optionally together with one or more other components, such as at least one photoinitiator component and / or at least one light-reflecting material component suspended in the composition, to light for a period of time; and forming a printed article comprising the polymerization product of the photopolymerizable macromer component(s) (i.e., polymerized macromer). In one aspect, disclosed herein are methods and compositions for photopolymerization processes, e.g., film-forming processes such as coating processes, as well as methods and compositions for making and using such photopolymerized materials. For example, the present disclosure provides a method of photopolymerizing coating an article, comprising the steps of: a) applying a photopolymerizable compound and / or composition of the present disclosure to a surface; and b) exposing the photopolymerizable compound and / or composition, including at least one photopolymerizable macromer component disclosed herein, optionally together with one or more other components, such as at least one photoinitiator component and / or at least one light-reflecting material component suspended in the composition, to light for a period of time; and forming a solid coating comprising the polymerization product of the photopolymerizable macromer component(s) (i.e., polymerized macromer). In other aspects, the present disclosure provides polymerization products of macromers (which may be referred to as prepolymers), where the macromers have been polymerized, for example, by one or more of the methods disclosed herein. Additionally, the present disclosure provides articles, sometimes referred to as polymeric articles, made from the photopolymerizable compounds or compositions disclosed herein, optionally by one or more of the methods disclosed herein. The photopolymerized macromers or photopolymerized articles may be non-toxic articles. Furthermore, the articles may include biodegradable photopolymerized macromers, optionally in admixture with a non-toxic amount of a photoinitiator. In one aspect, the polymeric article is wholly or partially biodegradable under physiological conditions. However, in another aspect, the polymeric article is not biodegradable under physiological conditions.

[0007] Also provided herein are photopolymerizable compositions comprising at least one photopolymerizable macromer component described herein, optionally in combination with one or more other components, such as a diluent, a photoinitiator, a colorant, and / or a light-reflecting component. For example, provided herein are photopolymerizable compositions for stereolithography, comprising at least one photopolymerizable macromer component, optionally in combination with one or more other components, such as a diluent, a photoinitiator, a colorant, and / or a light-reflecting component. The present disclosure further provides a photopolymerizable composition for producing a continuous liquid interface, comprising at least one photopolymerizable macromer component disclosed herein, optionally in combination with one or more other components, such as a diluent, a photoinitiator, a colorant, and / or a light-reflecting component. The present disclosure further provides a photopolymerizable ink composition comprising at least one photopolymerizable macromer component disclosed herein. The ink composition may also optionally contain one or more other components, such as a diluent, a photoinitiator, a colorant, and / or a light-reflecting component. The present disclosure further provides a photopolymerizable compound, also referred to herein as a macromer, comprising a multiaxial central core (CC) and two to four arms extending from the central core having the formula (A)-(B) or (B)-(A), wherein at least one of the arms comprises a photoreactive functional group (Q), and wherein (A) is the polymerization product of a monomer selected from trimethylene carbonate (also referred to herein as T or TMC) and ε-caprolactone (also referred to herein as caprolactone, or C or CAP), while (B) is the polymerization product of a monomer selected from glycolide, lactide, and p-dioxanone. The macromer may be the photopolymerizable macromer component in the compositions and methods disclosed herein and may be photopolymerized to provide an article.

[0008] The present disclosure further provides a composition comprising a plurality of compounds, each of which comprises a difunctional central core and one or two arms extending from the central core, each arm terminating in a hydroxy group. The hydroxy group may also be referred to as an end group. In this case, the central core is a difunctional core, and at least one of the two functional groups, and up to both of the functional groups on the central core, have reacted with a monomer to form an arm. These compounds can be used, for example, to form photopolymerizable macromers useful in the methods and compositions disclosed herein. The present disclosure also provides a composition comprising a plurality of compounds, each of which comprises a trifunctional central core and one, two, or three arms extending from the central core, each arm terminating in a hydroxy group. In this case, the central core is a trifunctional core, and at least one of the three functional groups, and up to all three of the functional groups on the central core, have reacted with a monomer to form an arm. These compounds can be used, for example, to form photopolymerizable macromers useful in the methods and compositions disclosed herein. The present disclosure further provides compositions comprising a plurality of compounds, each of which comprises a tetrafunctional central core and one, two, three, or four arms extending from the central core, each arm terminating in a hydroxy group. In this case, the central core is a tetrafunctional core, and at least one of the four functional groups, and up to all four of the functional groups on the central core, have reacted with a monomer to form an arm. These compounds can be used, for example, to form photopolymerizable macromers useful in the methods and compositions disclosed herein. Optionally, any of the compositions of the present disclosure, before being cured, may contain an effective amount of photoinitiator, i.e., an amount of photoinitiator effective to achieve polymerization of the photopolymerizable compound when the composition is exposed to radiation emitted from a non-natural light source that delivers light of a selected wavelength suitable to activate the photoinitiator.

[0009] In one aspect, the present disclosure provides a method of 3D printing, also known as additive printing, e.g., stereolithography, comprising providing a polymerizable composition as disclosed herein having a photopolymerizable compound and a photoinitiator, heating the composition to a molten state, depositing the molten composition into a desired shape, and exposing the desired shape to light effective to activate the photoinitiator to polymerize the photopolymerizable compound in the polymerizable composition.

[0010] The above and additional features of the present disclosure, and the manner in which they are obtained, will become apparent, and the disclosure will be best understood by reference to the following more detailed description. All references disclosed herein are incorporated by reference in their entirety as if each were individually incorporated. This Summary is provided to introduce certain concepts in a simplified form that are described in more detail below in the Detailed Description. Unless otherwise specified, this Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. The details of one or more embodiments are set forth in the following description. Features illustrated or described in connection with one exemplary embodiment may be combined with features of other embodiments. Accordingly, any of the various embodiments described herein can be combined to provide further embodiments. Aspects of the embodiments can be modified as necessary to employ concepts from the various patents, applications, and / or publications identified herein to provide further embodiments. Other features, objects, and advantages will be apparent from the specification, drawings, and claims.

[0011]

[0013] Exemplary features of the present disclosure, its characteristics and various advantages will be apparent from the accompanying drawings and the following detailed description of various embodiments. Non-limiting and non-exclusive embodiments are described with reference to the accompanying drawings, in which like labels or reference numbers refer to like parts throughout the various views unless otherwise specified. The sizes and relative positions of elements in the figures are not necessarily drawn to scale. For example, the shapes of the various embodiments have been selected, enlarged, and positioned to improve the readability of the drawings. The particular shapes of the depicted elements have been selected to facilitate recognition of the figures.

[0014] One or more embodiments are described below with reference to the accompanying drawings. [Brief explanation of the drawings]

[0012] [Figure 1]Figures 1A-1D show proton NMR spectra of triaxial BCPE polymers (BCPE4, BCPE6, BCPE9, and BCPE11, respectively). The peaks of the methacrylate protons are labeled: the methacrylate terminal alkenyl protons associated with TMC / caprolactone upfield (arrows) and with glycolide downfield (asterisks). [Figure 2] Figures 2A-2D show proton NMR spectra of linear BCPE polymers (BCPE5, BCPE7, BCPE10, and BCPE12, respectively). Methacrylate group proton peaks: TMC / caprolactone-related (arrow) upfield and glycolide-related (asterisk) methacrylate terminal alkenyl protons downfield. [Figure 3] 1 shows the rate of change in strength versus time for BCPE4-BCPE7 photopolymerized polymer films of the present disclosure. [Figure 4] 1 shows the moisture content over time for BCPE4-BCPE7 photopolymerized polymer films of the present disclosure. [Figure 5] 1 shows the mass loss over time for BCPE4-BCPE7 photopolymerized polymer films of the present disclosure. [Figure 6] 1 shows the effect of glycolide concentration on the mass loss rate of photopolymerized polymer films of the present disclosure. [Figure 7] 1 is a graph showing the increase in kinematic viscosity and molecular weight of thiolated polymers of the present disclosure after exposure to increasing light cure conditions. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention may be understood more readily by reference to the following detailed description of preferred embodiments of the present disclosure and the examples included therein.

[0014] Briefly, in one aspect, the present disclosure provides compounds and compositions useful for additive printing, particularly additive printing such as stereolithography (SLA), in which macromers are photopolymerized to form manufactured articles. Exemplary compounds include a multiaxial central core (CC) and two to four arms of the formula (A)-(B) or (B)-(A) extending from the central core, at least one of the arms comprising a photoreactive functional group (Q), wherein (A) is the free radical polymerization product of a monomer selected from trimethylene carbonate (T) and ε-caprolactone (C), while (B) is the free radical polymerization product of a monomer selected from glycolide, lactide, and p-dioxanone. In one aspect, the present disclosure provides a polymerizable composition. The composition includes one or more photopolymerizable compounds, also referred to herein as macromers, photopolymerizable macromers, or photopolymerizable macromer components. In one embodiment, the photopolymerizable compound is monofunctional, in that there is one mole of photoreactive group per mole of compound. In one embodiment, the photopolymerizable compound is multifunctional, e.g., difunctional, trifunctional, tetrafunctional, and / or pentafunctional. Higher functionality materials having 6 to 18 reactive sites (i.e., Q groups as described herein) are further contemplated by the present disclosure. In addition, the composition may include relatively low molecular weight species and / or relatively high molecular weight species. In one aspect, the macromer may include a reactive group, such as a photopolymerizable group, sometimes referred to herein as a photoreactive group or photocurable group. In one embodiment, the photoreactive group is an allylic or vinylic reactive group, such as an unsaturated functional group of an acrylate (including methacrylate), or other allylic and vinylic reactive groups. In one embodiment, the photoreactive group is a thiol (—SH) group. In embodiments, the macromers will typically have a molecular weight of less than 250,000 Da, or less than 200,000 Da, or less than 150,000 Da, or less than 100,000 Da, or less than 50,000 Da, or less than 25,000 Da, or less than 20,000 Da, or less than 15,000 Da, or less than 10,000 Da, or less than 9,000 Da, or less than 8,000 Da, or less than 7,000 Da, or less than 6,000 Da, or less than 5,000 Da.

[0015] In one embodiment, the present disclosure provides a compound comprising a central core and a plurality (e.g., 2-4) arms extending from the central core, each arm terminating (i.e., terminating) in a hydroxy group. The compound has the formula CC-[arm] n where CC represents a central core, and n is selected from the range of 2 to 18, or 2 to 14, or 2 to 8, or 2 to 6, or 2 to 4. Each arm is formed by polymerization of a monomer selected from two groups, which are designated Group A and Group B. Thus, more specifically, in the compounds of the present disclosure, CC-[arm] n can be written as either CC-[(A)p-(B)q-OH]n or CC-[(B)q-(A)p-OH]n, where each of (A)p-(B)q and (B)q-(A)p represents an arm. Optionally, the terminal functional group of the arm is indicated; an exemplary terminal functional group is hydroxy. In the above formula, A represents a polymerization product of one or more monomers including, and optionally selected only from, trimethylene carbonate (T or TMC) and caprolactone (C or CAP), and p represents the number of monomers polymerized to form polymerization product A, where p is selected from 1 to 40, or 1 to 30, or 1 to 20, or 1 to 10. In the above formula, B represents a polymerization product of one or more monomers including, and optionally selected only from, glycolide (G or GLY), lactide (L or LAC), and p-dioxanone (D or DOX), and q represents the number of monomers polymerized to form polymerization product B, where q is selected from 1 to 40, or 1 to 30, or 1 to 20, or 1 to 10. For example, the formula CC-[arm] n When a compound of formula CC-[arm] is formed from a trifunctional central core and A is added to CC before the addition of B, the compound of formula CC-[arm] ncan be written as CC-[(A)p-(B)q-OH]3. In this example, if A is formed by the polymerization of two Ts and one C, then p is 3 and A is independently selected within each arm from TTT, TTC, TCT, TCC, CCC, CCT, CTC, and CTT. Continuing this example, if B is formed by the polymerization of one G, then q is 1 and B is G. In this example, each arm has a chemical formula selected from TTTG, TTCG, TCTG, TCCG, CCCG, CCTG, CTCG, and CTTG. Exemplary compounds of the present disclosure can be represented as CC-[arm]3, where each arm is independently selected from TTTG-OH, TTCG-OH, TCTG-OH, TCCG-OH, CCCG-OH, CCTG-OH, CTCG-OH, and CTTG-OH, or as either CC-[(T,T,C)-(G)-OH]3 or CC-[(T,T,C)3-(G)1-OH]3.

[0016] In one aspect, the present disclosure provides a method for treating a medicament comprising administering to a subject a subject, each of which is a CC-[arm] nAlso provided is a composition comprising a plurality of compounds described in Formula (I). For example, in one embodiment, the present disclosure provides a composition comprising a plurality of compounds, wherein each of the plurality of compounds comprises a central core, each compound having two arms extending from the central core, each arm terminating in a hydroxy group, such that each compound can be represented by the formula CC-[arm]2. Alternatively, the present disclosure provides a composition comprising a plurality of compounds, wherein each of the plurality of compounds comprises a central core, each compound having three arms extending from the central core, each arm terminating in a hydroxy group, such that each compound can be represented by the formula CC-[arm]3. As a further alternative, the present disclosure provides a composition comprising a plurality of compounds, each of the plurality of compounds comprises a central core, each compound having four arms extending from the central core, each arm terminating in a hydroxy group, such that each compound can be represented by the formula CC-[arm]4. In the composition, each of the plurality of compounds has the same number of arms, and each has the same order of A and B groups selected from CC-[(A)-(B)]n and CC-[(B)-(A)]n. Accordingly, in six separate embodiments (a) through (f), the present disclosure provides: (a) a composition comprising a plurality of compounds of formula CC-[(A)-(B)]2; (b) a composition comprising a plurality of compounds of formula CC-[(A)-(B)]3; (c) a composition comprising a plurality of compounds of formula CC-[(A)-(B)]4; (d) a composition comprising a plurality of compounds of formula CC-[(B)-(A)]2; (e) a composition comprising a plurality of compounds of formula CC-[(B)-(A)]3; and (f) a composition comprising a compound of formula CC-[(B)-(A)]4.

[0017] In one embodiment, the present disclosure provides a composition comprising a plurality of compounds, each of the plurality of compounds comprising a difunctional central core and one or two arms extending from the central core, each arm terminating in a hydroxy group, wherein the central core is a difunctional core and at least one of the two functional groups, and up to both of the functional groups on the central core, have reacted with a monomer to form an arm. In one embodiment, the present disclosure provides a composition comprising a plurality of compounds, each of the plurality of compounds comprising a trifunctional central core and one, two, or three arms extending from the central core, each arm terminating in a hydroxy group, wherein the central core is a trifunctional core and at least one of the three functional groups, and up to all three of the functional groups on the central core, have reacted with a monomer to form an arm. In one embodiment, the present disclosure provides a composition comprising a plurality of compounds, each of the plurality of compounds comprising a tetrafunctional central core and one or two or three or four arms extending from the central core, each arm terminating in a hydroxy group, wherein the central core is a tetrafunctional core, and at least one of the four functional groups, and up to all four of the functional groups on the central core, have reacted with a monomer to form an arm.

[0018] Each arm of the plurality of compounds can be represented by the formula (A)-(B). Alternatively, each arm of the plurality of compounds can be represented by the formula (B)-(A). If the composition is prepared by reacting a central core with a monomer of Group A, followed by reacting the reaction product with a monomer(s) selected from Group B, the compounds in the composition will have the formula CC-[(A)-(B)]. However, if the composition is prepared by reacting a central core with a monomer of Group B, followed by reacting the reaction product with a monomer(s) selected from Group A, the compounds in the composition will have the formula CC-[(B)-(A)].

[0019] In one embodiment, the present disclosure provides a composition comprising a plurality of compounds, each of which comprises a difunctional central core and one or two arms extending from the central core, each arm terminating in a hydroxy group. In this case, the central core is a difunctional core, and at least one of the two functional groups, and up to both of the functional groups on the central core, reacts with a monomer to form an arm; therefore, the compound can be generally represented by one or more of CC-[(A)-(B)] and CC-[(A)-(B)], where CC is the difunctional core. Alternatively, if a group B monomer reacts with CC before reacting with a group A monomer, the compound of the composition can be generally represented by one or more of CC-[(B)-(A)] and CC-[(B)-(A)], where CC is the difunctional core. In one embodiment, the present disclosure provides a composition comprising a plurality of compounds, each of which comprises a trifunctional central core and one, two, or three arms extending from the central core, each arm terminating in a hydroxy group. In this case, the central core is a trifunctional core, and at least one of the three functional groups, and up to all three of the functional groups on the central core, reacts with a monomer to form an arm; therefore, the compound can be generally represented by one or more of CC-[(A)-(B)], CC-[(A)-(B)], and CC-[(A)-(B)], where CC is the trifunctional core. Alternatively, if a Group B monomer reacts with CC before reacting a Group A monomer, the compound of the composition can be generally represented by one or more of CC-[(B)-(A)], CC-[(B)-(A)], and CC-[(B)-(A)], where CC is the trifunctional core. In one embodiment, the present disclosure provides a composition comprising a plurality of compounds, each of the plurality of compounds comprising a tetrafunctional central core and one, two, three, or four arms extending from the central core, each arm terminating in a hydroxy group. In this case, the central core is a tetrafunctional core, and at least one of the four functional groups, and up to all four of the functional groups on the central core, reacts with a monomer to form an arm; thus, the compound can be generally represented by one or more of CC-[(A)-(B)]1, CC-[(A)-(B)]2, CC-[(A)-(B)]3, and CC-[(A)-(B)]4, where CC is the tetrafunctional core. Alternatively, if the Group B monomers are reacted with CC prior to reaction of the Group A monomers, the compounds of the composition can be generally represented by one or more of CC-[(B)-(A)]1 and CC-[(B)-(A)]2 and CC-[(B)-(A)]3 and CC-[(B)-(A)]4, where CC is a tetrafunctional core. In one aspect, the present disclosure provides a multi-arm compound described herein, wherein the arms terminate with a Q group, and the Q group is photopolymerizable. In one embodiment, an exemplary Q group can contain a photopolymerizable thiol group. In one embodiment, an exemplary Q group contains a photopolymerizable carbon-carbon double bond; for example, the Q group can contain a vinyl group, such as those present in acrylate or methacrylate groups, each of which has a photopolymerizable carbon-carbon double bond. For example, a Q group containing a photopolymerizable moiety, such as a photopolymerizable thiol or carbon-carbon double bond, can be introduced into the multi-arm compound described herein by reacting the terminal hydroxy group with a suitable reagent. Methods for converting a hydroxy group to a thiol-containing group or a carbon-carbon double bond-containing group are generally known and may be used to prepare the compounds of the present disclosure, examples of which are provided herein. The Q group contains a photoreactive group, particularly a photoreactive group that allows for polymerization of the Q-containing macromer; the Q group may also contain additional atoms that affect the photoreactivity of the photoreactive group (e.g., a carbonyl group adjacent to a carbon-carbon double bond, as exemplified herein) and / or additional atoms used to introduce the photoreactive group into the macromer; for example, a succinate ester may be used to introduce a thiol group, as exemplified herein.

[0020] For example, a multi-arm compound having a terminal hydroxy group may be reacted with a reactive acrylate or methacrylate compound, such as methacrylic anhydride, acrylic anhydride, methacryloyl chloride, or acryloyl chloride, to convert the hydroxy group to a Q group containing a photopolymerizable carbon-carbon double bond. For example, a multi-arm compound having a terminal hydroxy group disclosed herein may be subjected to an esterification reaction to convert the hydroxy group to a Q group containing a photopolymerizable thiol group. One method of esterification is to add stoichiometric amounts of a macromer and a mercaptocarboxylic acid compound in the presence of a carbodiimide (e.g., N,N'-dicyclohexylcarbodiimide) and a catalyst (e.g., dimethylaminopyridine). Examples of mercaptocarboxylic acids include, but are not limited to, the following compounds: 3-mercaptopropionic acid, thiolactic acid, thioglycolic acid, mercaptobutyric acid, mercaptohexanoic acid, mercaptobenzoic acid, mercaptoundecanoic acid, mercaptooctanoic acid, and n-acetylcysteine. For example, a multi-arm compound having a terminal hydroxy group disclosed herein may be reacted with thiolactic acid, in which case the resulting Q group has the formula -C(=O)-CH2-SH attached to the terminal oxygen of the multi-arm compound.

[0021] Another exemplary method for forming a thiol-functionalized macromer is to first modify a hydroxy-terminated macromer to form a terminal carboxylic acid group. One example is reacting a hydroxy-terminated macromer with succinic anhydride. Macromers with terminal carboxylic acid groups can be reacted with mercaptoalcohols via esterification or with mercaptoamines to form amide bonds. Some examples of mercaptoalcohols include, but are not limited to: mercaptopropanol, mercaptohexanol, mercaptooctanol, and mercaptoundecanol. Some examples of mercaptoamines include, but are not limited to: cysteine, glutathione, 6-amino-1-hexanethiol hydrochloride, 8-amino-1-octanethiol hydrochloride, and 16-amino-1-hexadecanethiol hydrochloride. For example, the multi-arm compounds with terminal hydroxy groups disclosed herein can be reacted with succinic anhydride to form an intermediate, which can then be reacted with cysteine ​​to introduce a terminal thiol group. In this case, the resulting Q group has the formula -C(=O)CH2CH2C(=O)NH-C(COOH)-CH2SH attached to the terminal carbon of the multi-arm compound. Yet another method for forming thiol-functionalized macromers is to react a macromer having a terminal hydroxy group with a lactone monomer having a pendant thiol group, which occurs in a third step, ring-opening polymerization.

[0022] In one aspect, the present disclosure provides a composition containing the photopolymerizable compound identified above, optionally in combination with one or more additional components. The photopolymerizable compound identified above comprises a central core and one or more arms having a Q terminal group. In one aspect, all of the macromers present in the composition contain the same central core. For example, all of the macromer components of the composition are prepared from trimethylolpropane or pentaerythritol. However, in one aspect, the composition of the present disclosure contains a mixture of macromer components, for example, some of the macromer components are triaxial, e.g., formed from trimethylolpropane, while other macromer components of the same composition are tetraaxial, e.g., formed from pentaerythritol.

[0023] In one aspect, the present disclosure provides a composition comprising a plurality of compounds as identified above, each of which incorporates the same (but not the same number) monomers of the same identity used to form the A and B groups. The compounds differ from one another in the number of polymerized monomer units present in their arms, more specifically, in the number of polymerized monomer units present in the A group and / or the number of polymerized monomer units present in the B group. For example, the A group is formed from a monomer selected from trimethylene carbonate (T) and caprolactone (C), but the number of T-derived units and the number of C-derived units in an arm may differ between the arms of the compound and may also differ between the arms of different compounds within the plurality of compounds present in the composition. Similarly, the B group is formed from a monomer selected from glycolide (G), lactide (L), and p-dioxanone (D), but the number of G-derived units, the number of L-derived units, and the number of D-derived units in an arm may differ between the arms of the compound and may also differ between the arms of different compounds within the plurality of compounds present in the composition. For example, the composition may comprise a group each having the formula CC-[arm] n and each arm is written as (A)-(B) rather than (B)-(A), then the composition includes multiple compounds each having the formula CC-[(A)-(B)]2. The number of compounds in the multiple differs in the number of monomer units used to form the A and B groups. Thus, if each of the multiple compounds has the formula CC-[(A)p-(B)q]2, then the sum of p and q can be 2 (where p and q are each 1), or the sum can be 3 (where one of p and q is 1 and the other of p and q is 2), or the sum can be 4 (where p and q are each 2, or one of p and q is 1 and the other of p and q is 3). For example, the formula CC-[arm] n When a compound of formula CC-[arm] is formed from a trifunctional central core and A is added to CC before the addition of B, the compound of formula CC-[arm] ncan be written as CC-[(A)p-(B)q-OH]3. In this example, if A is formed by the polymerization of two Ts and one C, then p is 3 and A is independently selected within each arm from TTT, TTC, TCT, TCC, CCC, CCT, CTC, and CTT. Continuing this example, if B is formed by the polymerization of G, then q is 1 and B is G. In this example, each arm has a chemical formula selected from TTTG, TTCG, TCTG, TCCG, CCCG, CCTG, CTCG, and CTTG. Exemplary compounds of the present disclosure can be represented as CC-[arm]3, where each arm is independently selected from TTTG-OH, TTCG-OH, TCTG-OH, TCCG-OH, CCCG-OH, CCTG-OH, CTCG-OH, and CTTG-OH, or as either CC-[(T,T,C)-(G)-OH]3 or CC-[(T,T,C)3-(G)1-OH]3.

[0024] As mentioned above, each arm is formed by polymerization of a monomer selected from two groups, designated Group A and Group B. Thus, more specifically, in the compounds of the present disclosure, CC-[arm] n is CC-[(A)p-(B)q-OH] n , or CC-[(B)q-(A)p] n where (A)p-(B)q and (B)q-(A)p each represent an arm. In the above formula, A represents a polymerization product of one or more monomers including, and optionally selected only from, trimethylene carbonate (T) and caprolactone (C), and p represents the number of monomers polymerized to form polymerization product A, and is selected from 1 to 40, or 1 to 30, or 1 to 20, or 1 to 10. In the above formula, B represents a polymerization product of, and optionally selected from, one or more monomers including, glycolide (G), lactide (L), and p-dioxanone (D), and q represents the number of monomers polymerized to form polymerization product B, and is selected from 1 to 40, or 1 to 30, or 1 to 20, or 1 to 10.

[0025] The compounds of the present disclosure having hydroxyl end groups, i.e., arms terminating in hydroxyl groups, are useful for preparing corresponding photopolymerizable compounds and compositions containing such photopolymerizable compounds. The hydroxyl end groups can be converted into photopolymerizable groups by techniques known in the art and exemplified herein. These photopolymerizable groups are represented herein by the abbreviation "Q."

[0026] In one embodiment, the present disclosure provides a compound comprising a central core and a plurality of (e.g., 2-4) arms extending from the central core, each arm terminating in a polymerizable group (Q). The compound has the formula CC-[arm-Q] n where CC represents a central core, and n is selected from the range of 2 to 18, or 2 to 14, or 2 to 8, or 2 to 6, or 2 to 4. Each arm is formed by polymerization of a monomer selected from two groups, which are designated Group A and Group B. Thus, more specifically, in the compounds of the present disclosure, CC-[arm] n can be expressed as either CC-[(A)p-(B)qQ]n or CC-[(B)q-(A)pQ]n, where (A)p-(B)q and (B)q-(A)p each represent an arm. Optionally, the terminal functional group of the arm may be indicated, where Q generally represents a photoreactive group terminal functional group. In the above formula, A represents a polymerization product of one or more monomers including, and optionally selected only from, trimethylene carbonate (T) and caprolactone (C), and p represents the number of monomers polymerized to form polymerization product A, where p is selected from 1 to 40, or 1 to 30, or 1 to 20, or 1 to 10. In the above formula, B represents a polymerization product of one or more monomers including, and optionally selected only from, glycolide (G), lactide (L), and p-dioxanone (D), and q represents the number of monomers polymerized to form polymerization product B, where q is selected from 1 to 40, or 1 to 30, or 1 to 20, or 1 to 10.

[0027] In embodiments, the present disclosure provides photopolymerizable compounds and compositions containing such compounds, wherein the compound is described by one of the following: the compound is or includes the structure CC-[ABQ]n, where n is 2; the compound is or includes the structure CC-[ABQ]n, where n is 3; the compound is or includes the structure CC-[ABQ]n, where n is 4; the compound is or includes the structure CC-[BAQ]n, where n is 2; the compound is or includes the structure CC-[BAQ]n, where n is 3; the compound is or includes the structure CC-[BAQ]n, where n is 4. Optionally, the compound has four arms, a molecular weight of less than 40,000 g / mol, or less than 20,000 g / mol, and is a solid at room temperature. Optionally, the compound has three arms, a molecular weight of less than 15,000 g / mol, and is a liquid at room temperature. Optionally, the compound has two arms, a molecular weight of less than 5,000 g / mol, and is a liquid at room temperature.

[0028] In one embodiment, the photopolymerizable compounds of the present disclosure have relatively short arms, e.g., 1 to 10 monomer residues / arms. As used herein, "monomer residue" refers to the polymerization product of a monomer, i.e., the structure of a monomer after the monomer is incorporated into a polymer, thus providing the monomer residue in the polymer. In one embodiment, when compounds of the present disclosure are used in laminate printing, they must be in a fluid state: either the compound itself is fluid or the compound is dissolved in a solvent and / or diluent to provide a fluid composition. If the arms are too long, compositions containing the compound are typically too viscous to be useful in laminate printing, such as SLA, unless the composition contains a significant amount of solvent or diluent to dilute the compound. In that case, the laminate printing process may require the use of undesirably large amounts of solvent. Advantageously, if the arms are relatively short, the compound itself can be fluid at the application temperature of the laminate printing process, which may be higher than room temperature, resulting in the compound having to be heated to achieve a molten state, or the compound may be dissolved in a solvent at a relatively high concentration, still resulting in a low-viscosity solution.

[0029] In any embodiment, the compounds of the present disclosure and compositions containing such compounds can be described by one or more of the following features characterizing the A region (also referred to as block) of the compound: having a block A comprising residues formed from trimethylene carbonate (TMC or T), i.e., block A that is the polymerization product or residue of TMC; having a block A comprising residues formed from caprolactone (CAP or C); having a block A comprising residues formed from TMC and CAP; at least 90% of the residues of block A are formed from TMC or CAP. the compound contains 1 to 45 or 2 to 45 residues formed from TMC; the compound contains 1 to 15 or 2 to 15 residues formed from TMC; the compound contains 1 to 10 or 2 to 10 residues formed from TMC; Region A has a molecular weight of 102 to 2500 g / mol; Region A has a molecular weight of 102 to 1000 g / mol; Region A has a molecular weight of 102 to 900 g / mol; each A region contains 2 to 45 monomer residues; each A region contains 2 to 15 monomer residues; each A region contains 2 to 10 monomer residues. In any embodiment, the compounds of the present disclosure and compositions containing such compounds can be described by one or more of the following features characterizing the B blocks (also called regions) of the compound: each B block contains 1 to 45 or 2 to 45 monomer residues; each B block contains 1 to 15 or 2 to 15 monomer residues; each B block contains 1 to 10 or 2 to 10 monomer residues.

[0030] The compounds may also, or alternatively, be described by one or more of the following: the compound has a molecular weight of less than 40,000 g / mol; the compound has a molecular weight of less than 25,000 g / mol; the compound has a molecular weight of less than 10,000 g / mol. Photopolymerizable compositions of the present disclosure can optionally be described as having a viscosity of less than 50,000 mPa·s at room temperature; or having a viscosity of less than 30,000 mPa·s at room temperature; or having a viscosity of less than 20,000 mPa·s at room temperature. The composition may contain a diluent. The diluent may be reactive or non-reactive. Reactive diluents undergo photopolymerization when exposed to light (UV or visible light), while non-reactive diluents are inert to such light exposure. A typical reactive diluent is PEG-diacrylate (PEG-DA or PEGDA).

[0031] The following are numbered exemplary embodiments of the present disclosure. 1) A photopolymerizable compound comprising a polyaxial central core (CC) and two to four arms of the formula (A)-(B) or (B)-(A) extending from the central core, at least one of the arms comprising a photoreactive functional group (Q), wherein (A) is a ring-opening polymerization product from a monomer selected from trimethylene carbonate (T) and ε-caprolactone (C), and (B) is a ring-opening polymerization product from a monomer selected from glycolide, lactide, and p-dioxanone. 2) A photocurable composition comprising one or more photopolymerizable compounds of embodiment 1, and optionally also containing a photopolymerization initiator. 3) a photoreactive multiaxial macromer compound comprising a central core (CC) and 2 to 4 arms extending from the central core, at least one of the arms comprising a photoreactive functional group (Q) and a block copolymer comprising a block A and a block B; a. Block A comprises residues formed from at least one of trimethylene carbonate (TMC) and ε-caprolactone (CAP), i.e., one or both; and b. A multiaxial macromer compound, wherein block B comprises residues formed from at least one of glycolide, lactide, and p-dioxanone, ie, one, two, or all three. 4) A photoreactive composition comprising one or more macromer compounds of embodiment 3. 5) A prepolymer compound of the photopolymerizable compound of embodiment 1, wherein the central core (CC) is attached to (A) of one or more arms of the formula (A)-(B), and (B) has a hydroxy end group. 6) A prepolymer compound of the photopolymerizable compound of embodiment 1, wherein the central core (CC) is linked to (B) of one or more arms of the formula (B)-(A), and (A) has a hydroxy end group. 7) The compounds and compositions of embodiments 1-6, wherein each of (A) and (B) comprises at least one but not more than 10 monomer residues. 8) The compounds and compositions of embodiments 1-6, wherein each of (A) and (B) comprises at least one but not more than eight monomer residues. 9) The compounds and compositions of embodiments 1-6, wherein each of (A) and (B) comprises at least one but not more than six monomer residues. 10) The compounds and compositions of embodiments 1-6, wherein each of (A) and (B) comprises at least one but not more than four monomer residues. 11) The compounds and compositions of embodiments 1-10, wherein the compound has a molecular weight of less than 5,000 g / mol. 12) The compounds and compositions of embodiments 1-10, wherein at least 90% by weight of the compounds having a central core and arms with (A) and (B) regions have a molecular weight of less than 5,000 g / mol. 13) The compounds and compositions of embodiments 1-10, wherein the compound has a molecular weight of less than 4,000 g / mol. 14) The compounds and compositions of embodiments 1-10, wherein at least 90% by weight of the compounds having a central core and arms with (A) and (B) regions have a molecular weight of less than 4,000 g / mol. 15) The compounds and compositions of embodiments 1-10, wherein the compound has a molecular weight of less than 3,000 g / mol. 16) The compounds and compositions of embodiments 1-10, wherein at least 90% by weight of the compounds having a central core and arms with (A) and (B) regions have a molecular weight of less than 3,000 g / mol.

[0032] Photopolymerizable compounds described herein having photopolymerizable Q groups, and compositions of the present disclosure containing such compounds, undergo polymerization upon sufficient exposure to light of an appropriate wavelength, optionally in the presence of a photoinitiator, and optionally in the presence of other ingredients. The appropriate wavelength, exposure time, and identity and amount of curing agent are selected taking into account the identity and amount of Q groups in the compounds and compositions, as is conventional in the art. Photopolymerization is sometimes referred to as radiation curing, in which case the photoinitiator may be referred to as the curing agent. Photoinitiators refer to organic (carbon-containing) molecules that generate reactive species when exposed to radiation. In one embodiment, the photoinitiator generates radically reactive species, rather than, for example, cationic or anionic reactive species. Photoinitiators are well-known components for the preparation of photopolymers used in light-curable coatings, adhesives, and dental restorations. For a photoinitiator to successfully cure a photoreactive polymer, the absorption band of the photoinitiator must overlap with the emission spectrum of the light source used for curing. Optionally, the photopolymerizable compositions disclosed herein include at least one photoinitiator that absorbs light at wavelengths of about 10 nm to about 770 nm, or about 100 nm to about 770 nm, or about 200 nm to about 770 nm, and all wavelengths in between. In one embodiment, the photoinitiator component includes a photoinitiator that absorbs light at wavelengths of 300 nm or greater, up to about 770 nm. In one embodiment, the photoinitiator component includes a photoinitiator that absorbs light at wavelengths of 365 nm or greater, up to about 770 nm. In one embodiment, the photoinitiator component includes a photoinitiator that absorbs light at wavelengths of 375 nm or greater, up to about 770 nm. In one embodiment, the photoinitiator component includes a photoinitiator that absorbs light at wavelengths of 400 nm or greater, up to about 770 nm. The wavelength selection depends on the photoinitiator's identity. Commercial photoinitiator suppliers indicate the appropriate wavelengths for a particular photoinitiator.

[0033] Polymer curing according to the present disclosure may be achieved using photoinitiators that generate free radicals. These photoinitiators can be used to cure thiol-containing polymers and double-bond-containing polymers with acrylate and / or methacrylate functionality. There are two types of free-radical-generating photoinitiators, designated Type I and Type II photoinitiators, that can be used according to the present disclosure. Type I photoinitiators are unimolecular free radical generators; upon absorption of UV-visible light, specific bonds within the initiator's structure undergo homolytic cleavage to generate free radicals. Homolytic cleavage occurs when electron bond pairs are homolytically split to free radical products. Examples of homolytic cleavage in some general classes of Type I photoinitiators are: benzoin ethers, benzil ketals, α-dialkoxy-acetophenones, α-hydroxy-alkylphenones, and acylphosphine oxides. Exemplary commercially available Type I photoinitiators are available from, for example, BASF, BASF Chemical Industries, Ltd. Available from SE (Ludwigshafen, Germany), including but not limited to, Irgacure™ 369, Irgacure™ 379, Irgacure™ 907, Darocur™ 1173, Irgacure™ 184, Irgacure™ 2959, Darocur™ 4265, Irgacure™ 2022, Irgacure™ 500, Irgacure™ 819, Irgacure™ 819-DW, Irgacure™ 2100, Lucirin™ T PO, Lucirin™ TPO-L, Irgacure™ 651, Darocur™ BP, Irgacure™ 250, Irgacure™ 270, Irgacure™ 290, Irgacure™ 784, Darocur™ MBF, and Irgacure™ 754, lithium phenyl-2,4,6-trimethylbenzoylphosphinate, magnesium phenyl-2,4,6-trimethylbenzoylphosphinate, and sodium phenyl-2,4,6-trimethylbenzoylphosphinate. Type II photoinitiators require, in addition to the photoinitiator, a co-initiator (usually an alcohol or amine) from which the functional hydrogen can be easily abstracted. Absorption of UV-visible light by the Type II photoinitiator creates an excited electronic state in the photoinitiator, which abstracts a hydrogen from the co-initiator, splitting the bonding electron pair in the process. Benzophenone, thioxanthone, and benzophenone-type photoinitiators are the most common Type II photoinitiators. Further examples of some common Type II photoinitiators include riboflavin, eosin Y, and camphorquinone. The polymerization mechanism after free radical generation is similar to any free radical polymerization process. In one embodiment, the photoinitiator component in the composition of the present disclosure comprises a Type I photoinitiator. In one embodiment, the photoinitiator component in the composition of the present disclosure comprises a Type II photoinitiator. In one embodiment, a combination of a Type I photoinitiator and a Type II photoinitiator is present in the photopolymerizable composition of the present disclosure.

[0034] In any of the photopolymerizable compounds and compositions disclosed herein, Q can be a carbon-carbon double bond, such as a vinyl group. Exemplary vinyl groups are acrylate and methacrylate groups. In a further aspect, photopolymerizable compounds having one or more Q groups undergo photopolymerization when exposed to light having a wavelength of, for example, 300-450 nm, or 300-425 nm, or 350-450 nm, or 350-425 nm, or 365-405 nm. In one embodiment, the compounds and compositions undergo photopolymerization when exposed to UV radiation. In any of the photopolymerizable compounds and compositions described herein, Q can be a thiol group. In a further aspect, photopolymerizable compounds having one or more Q groups undergo photopolymerization upon exposure to light having a wavelength of, for example, 300-450 nm, or 300-425 nm, or 350-450 nm, or 350-425 nm, or 365-405 nm. In one embodiment, the compounds and compositions undergo photopolymerization upon exposure to UV radiation.

[0035] In general, the photoinitiator concentration required for thiol free radical polymerization using a photoinitiator is much higher than that required when the Q group contains a photopolymerizable carbon-carbon double bond. In the presence of a thiol group, the photoinitiator can initiate a thiol group, but two thiol groups can only polymerize when two thiyl radicals meet. Furthermore, the combination of two thiyl radicals results in the termination of the radical group, thus requiring a high concentration of photoinitiator. When the photopolymerizable group is a carbon-carbon double bond or contains a carbon-carbon double bond (e.g., a vinyl group), a single free radical can initiate and propagate many vinyl groups before terminating. Therefore, when photopolymerization proceeds via thiol groups, it is beneficial to have a relatively high density of thiol groups. A lower concentration of thiol end groups reduces both the probability of thiyl radical generation and the probability that two thiyl radicals will combine to cause polymerization. In this regard, low molecular weight (ie, preferably <5000 Da, more preferably <3000 Da, even more preferably <2000 Da) multi-arm thiol compounds are preferred for the photopolymerization process of the present disclosure.

[0036] In any of the photopolymerizable compositions described herein, compounds having only a single arm of the formula -(A)-(B)-Q or -(B)-(A)-Q may be present in some amount, typically a small amount. In one embodiment, the single-arm compound provides less than 20% by weight of the total weight of compounds having Q groups. In other embodiments, the single-arm compound provides less than 15%, or less than 10%, or less than 5%, or less than 4%, or less than 3%, or less than 2% by weight of the total weight of compounds having Q groups. In these compounds, the central core may be derived from either a difunctional central core (difunctional initiator), a trifunctional central core (trifunctional initiator), or a tetrafunctional central core (tetrafunctional initiator). In any of the photopolymerizable compositions described herein, a compound(s) selected from compounds comprising the formulas CC-Q, CC-AQ, and CC-BQ may be present in some amount. Compounds having the formula CC-Q will have a central core directly bonded to the photopolymerizable group Q. Compounds having the formula CC-AQ will have arms formed from monomer residues from Group A but not from Group B, which terminate in Q groups and are bonded to the central core CC. Compounds having the formula CC-BQ will have arms formed from monomer residues from Group B but not from Group A, which terminate in Q groups and are bonded to the central core CC. In these compounds, the central core may be derived from either a difunctional central core (difunctional initiator), a trifunctional central core (trifunctional initiator), or a tetrafunctional central core (tetrafunctional initiator). In any of the photopolymerizable compositions described herein, one or more compounds may be present in some amount, in which some of the arms terminate in Q end groups while others terminate in hydroxy end groups. Such compounds may arise when there is incomplete conversion of the hydroxy end groups to the corresponding reactive Q groups. An exemplary compound of this type may be written as {[(B)q-(A)p]n-}m-CC-{[(A)p-(B)qQ]}r, which describes a compound in which "m" of the arms terminate in hydroxy end groups and "r" of the arms terminate in Q end groups, where the sum of m and r is the functionality of the central core (CC). For example, when the central core is difunctional, m can be 1 and r can be 1. As another example, when the central core is trifunctional, m can be 1 and r can be 2. As yet another example, when the central core is trifunctional, m can be 2 and r can be 1. A corresponding situation can occur with compounds of formula {[(A)q-(B)p]n-}m-CC-{[(B)p-(A)qQ]}r.

[0037] In addition to photoinitiators, colorants, such as dyes, may be added to the photopolymerizable printing formulations described herein. The addition of dyes can achieve the goal of adjusting the formulation to a desired color. However, dyes for non-toxic and biocompatible formulations are typically used at concentrations of 2% by weight or less (see, for example, International Application PCT / US2016 / 059910, incorporated herein by reference, for teachings of polymerization compositions and dye use). For absorbable devices, most dyes are regulated by the FDA to a content of 0.1-0.3% by weight, as exemplified by the D&C Violet additive in most absorbable suture products. The combination of high dye concentrations with high photoinitiator concentrations results in significant toxicity in 3D photoprintable compositions, particularly in the resulting photoprinted articles.

[0038] In one aspect, the present disclosure provides a stereolithography (SLA) ink composition. The composition includes a photopolymerizable compound disclosed herein, also referred to as a photopolymerizable macromer. Optionally, the ink composition includes at least one photoinitiator component, typically at a total concentration of less than 2% by weight, or less than 1.5% by weight, or less than 1% by weight, or less than 0.9% by weight, or less than 0.8% by weight, or less than 0.7% by weight, or less than 0.6% by weight, or less than 0.5% by weight, or less than 0.25% by weight, or less than 0.1% by weight, based on the total weight of the polymerizable macromer. Also optionally, the SLA ink composition includes at least one light reflector component comprising a light reflector suspended in the composition, the light reflector component modulating the light dose of the composition compared to the light dose of the composition without the light reflector. Light reflectors suitable for this and other embodiments disclosed herein are disclosed in U.S. Provisional Patent Application No. 62 / 653,584, entitled "Methods and Compositions for Photopolymerizable Additive Manufacturing," filed April 6, 2018, to Poly-Med, Inc., inventors M.A. Vaughn and P. Saini. Other optional components of the ink composition are reactive diluents, non-reactive diluents, solvents, stabilizers, thixotropic materials, colorants, tracer materials, and conductive materials. For example, the additive may be a dye. Printed articles made with the SLA inks of the present disclosure may be colored due to the presence of a dye, or may have any desired property, such as, but not limited to, fluorescence, emissive properties, flexibility, rigidity, softness, friability, or combinations thereof, for at least a portion of the article.

[0039] The photopolymerizable compositions disclosed herein are made by combining the desired components, typically with stirring, to achieve a homogeneous composition. The desired composition may be mixed using a homogenizer. For example, the photopolymerizable compositions disclosed herein may be prepared by combining the components identified above, such as a photopolymerizable macromer and a photoinitiator. Optionally, the desired components may include a dispersant to aid in suspension. The listed components may optionally be heated prior to mixing. The listed components may optionally be placed under vacuum to remove air bubbles.

[0040] The methods disclosed herein include methods for producing articles, particularly non-toxic and biodegradable articles, using photopolymerizable compositions. For example, the compositions disclosed herein can be used in 3D printing processes as photopolymerizable or photocurable inks or resins. For example, the compositions disclosed herein can be used in stereolithography (SLA) 3D printing processes as photopolymerizable or photocurable inks or resins. The present disclosure provides a method for SLA printing of an article, comprising exposing a photopolymerizable composition comprising at least one photopolymerizable macromer compound disclosed herein and at least one photoinitiator component, typically at a total concentration of less than 1.0 wt %, to light for a period of time. Any of the photopolymerizable compositions disclosed herein can be used in the method for SLA printing of an article. For example, the photopolymerizable composition may comprise a reactive diluent or a non-reactive diluent. A reactive diluent is a diluent that participates in a polymerization reaction, e.g., the reactive diluent polymerizes with, for example, the macromer. The photopolymerizable composition of the present disclosure may also comprise a stabilizer, e.g., a free radical stabilizer. The method of printing an article by SLA according to the present disclosure may include a secondary curing step, which involves hardening the printed article. The secondary curing step involves exposing at least a portion of the printed article to undergo a second polymerization reaction. For example, a portion of the article may be exposed to radiation of the same or a different wavelength as used in the first polymerization step, and a photoinitiator, which may be the same or different from the photoinitiator reacted in the first polymerization step, is activated to polymerize unpolymerized or partially polymerized reactive groups. The secondary curing step may change the properties of the printed article. For example, after the initial printing step, the printed article is generally flexible and pliable. After exposing the outer surface of the printed article to a secondary curing step using radiation of a different wavelength, the outer surface of the printed article is hard and not pliable.

[0041] Methods of printing articles by SLA according to the present disclosure may include pre- and / or post-treatment of the printed article. For example, the printed article may be rinsed after printing, before a secondary curing step, after a secondary printing step, or after each of these steps. A printed article is an article obtained after the SLA 3D printing period is completed. The printed article may be a structure or a portion of a structure. The printed article may be in the form of a film, such as a coating printed on a surface. As used herein, the term printing is used to mean contacting a polymer composition with a surface to further polymerize the polymer composition. Printing may include contacting the polymer composition with a surface and then exposing it to UV and / or visible light to cause further polymerization. The surface contacted by the polymer composition may be any surface that contains a polymerized layer of the polymer composition. The printed article may or may not contain residual amounts of components of the photopolymerizable composition. For example, the printed article may include a diluent or photopolymerizable diluent, or a photopolymerization initiator. In one aspect, the printed article or the photopolymerizable composition may have additives. The additives may include thixotropic materials, colorants, tracer materials, or conductive materials. For example, the additive may be a dye. The printed article may be colored by the presence of a dye, or may have any property that at least a portion of the article possesses, such as, but not limited to, fluorescence, radioactivity, flexibility, rigidity, pliability, friability, or combinations thereof.

[0042] The method of SLA printing an article can include a photopolymerizable composition including a monomer or macromer capable of undergoing polymerization, such as a monomer or macromer having functional groups capable of undergoing photopolymerization to form an oligomer and / or polymer. In one aspect, the macromers and monomers can include ethylenically unsaturated aliphatic or aromatic reactive groups or end groups. The disclosed macromers and monomers function in the methods disclosed herein. A method for SLA printing an article includes photopolymerizing a photopolymerizable composition with light having a wavelength of about 10 nm to about 770 nm. As used herein, UV radiation has a wavelength of about 10 to 400 nm, and visible radiation has a wavelength of 390 to 770 nm. In one embodiment, a photopolymerizable composition that includes a light reflector component photopolymerizes with a shorter exposure time than a photopolymerizable composition that does not include a light reflector component under the same polymerization conditions.

[0043] A method for printing an article using SLA in a device for printing by SLA includes a photopolymerizable composition including a photoinitiator component. The photoinitiator component may include one or more photoinitiators and may also include other materials, such as diluents, excipients, inhibitors, or other solutions. In one embodiment, the photoinitiator component may be present at a concentration of about 0.05% to about 5.0% by weight of the photopolymerizable composition. In one embodiment, the photoinitiator component may be present at a concentration of less than 0.50% by weight of the photopolymerizable composition. In one embodiment, the photoinitiator component may be present at 0.25% by weight of the photopolymerizable composition. In one embodiment, the photoinitiator component may be present at less than 0.25% by weight of the photopolymerizable composition. In one embodiment, the photoinitiator component may be present at 0.10% by weight of the photopolymerizable composition. In one embodiment, the photoinitiator component may be present at less than 0.10% by weight of the photopolymerizable composition. A method for printing an article using SLA in a device for printing by SLA includes a photopolymerizable composition comprising at least one photoinitiator component that absorbs light at a wavelength of about 10 nm to about 770 nm. In one embodiment, the photoinitiator absorbs a wavelength of light of 300 nm or greater. In one embodiment, the photoinitiator absorbs a wavelength of light of 365 nm or greater. In one embodiment, the photoinitiator absorbs a wavelength of light of 375 nm or greater. In one embodiment, the photoinitiator absorbs a wavelength of light of 400 nm or greater. A method for printing an article using SLA in a device for printing by SLA includes a photopolymerizable composition comprising at least one photoinitiator that is a Type I, Type II, cationic photoinitiator, or a combination thereof. A method of printing an article using SLA in a device for printing by SLA includes photopolymerizing or curing a photopolymerizable composition that includes a photoinitiator component to a depth of less than 150 μm. In one embodiment, the method disclosed herein includes photopolymerizing or curing the photopolymerizable composition to a depth of about 5 μm to about 50 μm, and all depths therebetween. A method for printing an article using SLA in a device for printing by SLA includes a photopolymerizable composition including a light reflector component that includes a light reflector that is absorbable under physiological conditions. In one embodiment, the light reflector component includes a light reflector that is biocompatible with living organs. In one embodiment, the light reflector component includes a light reflector that is polymerized using at least one of a photopolymerizable macromer, a diluent, a light reflector, or a combination thereof.

[0044] The present disclosure includes polymeric articles formed from the compositions disclosed herein when the compositions are polymerized by the methods disclosed herein. The present disclosure includes articles (also referred to herein as printed articles) made from the compositions disclosed herein by the methods disclosed herein. In one embodiment, the article may be a medical device. In one embodiment, the article may be a portion of a medical device. In one embodiment, the article may be porous. In one embodiment, the article may be biodegradable under physiological conditions. In one embodiment, a biodegradable article may have a degradation time of about 3 days to about 5 years. In one embodiment, the article may not be biodegradable. In one embodiment, one portion of the article may be biodegradable and a second portion may not be biodegradable or may have a different degradation time than the first portion or the remainder of the article.

[0045] The article may also be drug-eluting, e.g., all or a portion of the article may elute a bioactive agent that was included in the photopolymerizable composition, including, but not limited to, profibrotic agents, antifungal agents, antimicrobial and antibiotic agents, anti-inflammatory agents, anti-scarring agents, immunosuppressants, immunostimulants, antiseptics, anesthetics, antioxidants, cell / tissue growth promoting factors, antineoplastic agents, anti-cancer agents, and agents that support ECM integration. Examples of fibrosis inducers include, but are not limited to, talcum powder, metallic beryllium and its oxides, copper, silk, silica, crystalline silicates, talc, quartz dust, and ethanol; components of the extracellular matrix selected from fibronectin, collagen, fibrin, or fibrinogen; polymers selected from the group consisting of polylysine, poly(ethylene-co-vinyl acetate), chitosan, N-carboxybutylchitosan, and RGD protein; vinyl chloride or vinyl chloride polymers; cyanoacrylates and crosslinkers. adhesives selected from the group consisting of bridged poly(ethylene glycol)-methylated collagen; inflammatory cytokines (e.g., TGFβ, PDGF, VEGF, bFGF, TNFα, NGF, GM-CSF, IGF-α, IL-1, IL-1β, IL-8, IL-6, and growth hormone); connective tissue growth factor (CTGF); bone morphogenetic proteins (BMPs) (e.g., BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, or BMP-7); leptin, and bleomycin, or analogs or derivatives thereof. Optionally, the device may additionally comprise a growth agent to stimulate cell proliferation. Examples of antiproliferative agents include dexamethasone, isotretinoin (13-cis retinoic acid), 17-β-estradiol, estradiol, 1α,25-dihydroxyvitamin D3, diethylstibesterol, cyclosporin A, L-NAME, all-trans retinoic acid (ATRA), and analogs and derivatives thereof (see U.S. Patent Application Publication No. 2006 / 0240063, incorporated by reference in its entirety). Examples of antifungal agents include, but are not limited to, polyene antifungals, azole antifungals, and echinocandins. Examples of antimicrobial agents and antibiotics include, but are not limited to, erythromycin, penicillin, cephalosporins, doxycycline, gentamicin, vancomycin, tobramycin, clindamycin, and mitomycin. Examples of anti-inflammatory agents include, but are not limited to, nonsteroidal anti-inflammatory agents such as ketorolac, naproxen, diclofenac sodium, and flurbiprofen.Examples of anti-scarring agents include, but are not limited to, cell cycle inhibitors such as taxanes, and immunomodulators such as sirolimus or biolimus (see, e.g., U.S. Patent Application Publication No. 2005 / 0149158, paragraphs 64-363 and in their entirety, the entire specification of which is incorporated by reference). Examples of immunosuppressants include, but are not limited to, glucocorticoids, alkylating agents, antimetabolites, and immunophilin-acting agents, such as cyclosporine and tacrolimus. Examples of immunostimulants include, but are not limited to, interleukins, interferons, cytokines, Toll-like receptor (TLR) agonists, cytokine receptor agonists, CD40 agonists, Fc receptor agonists, CpG-containing immunostimulatory nucleic acids, complement receptor agonists, or adjuvants. Examples of antiseptics include, but are not limited to, chlorhexidine and tibezonium iodide. Examples of anesthetics include, but are not limited to, lidocaine, mepivacaine, pyrrocaine, bupivacaine, prilocalne, and etidocaine. Examples of antioxidants include, but are not limited to, antioxidant vitamins, carotenoids, and flavonoids. Examples of cell growth promoting factors include, but are not limited to, epidermal growth factor, human platelet-derived TGF-β, endothelial growth factor, thymocyte-activating factor, platelet-derived growth factor, fibroblast growth factor, fibronectin, or laminin. Examples of antineoplastic / anticancer agents include, but are not limited to, paclitaxel, carboplatin, miconazole, leflunamide, and ciprofloxacin. Examples of agents that support ECM integration include, but are not limited to, gentamicin.

[0046] The articles of the present disclosure may contain a mixture of bioactive agents to achieve a desired effect. Thus, for example, an antimicrobial agent and an anti-inflammatory agent may be combined in a single article to provide a combined effect. Additionally, the present disclosure provides the following numbered exemplary embodiments: 1. a) i. at least one photopolymerizable macromer component; iii. at least one photoinitiator component; exposing a photopolymerizable composition comprising: b) forming a printed article comprising a polymerized form of the macromer component; 1. A method of photopolymerization printing an article, comprising: The photopolymerizable macromer component comprises a central core (CC) and a plurality of arms extending from the central core, all or substantially all of the arms terminating in a photopolymerizable group (Q); each arm is formed by polymerization of monomers selected from two groups, designated Group A and Group B; resulting in Region A and Region B, respectively, within the arm, where Region A represents the polymerization product of one or more monomers including, and optionally selected only from, trimethylene carbonate (T) and caprolactone (C), and Region B represents the polymerization product of one or more monomers including, and optionally selected only from, glycolide (G), lactide (L), and p-dioxanone (D). method. 2. The method of embodiment 1, wherein the photopolymerizable macromer compound has the formula CC-[arm-Q]n, where CC represents a central core and n is selected from a number ranging from 2 to 18, and each arm is formed by polymerization of a monomer selected from two groups, designated Group A and Group B, to provide a macromer of the formula CC-[(A)p-(B)qQ]n, or CC-[(B)q-(A)p)-Q]n, where each of (A)p-(B)q and (B)q-(A)p represents an arm, p is selected from 1 to 40, and q is selected from 1 to 40. 3. The method of embodiment 2, wherein the photopolymerizable macromer component is described by the formula CC-[(A)p-(B)qQ]n. 4. The method of embodiment 2, wherein the photopolymerizable macromer component is described by the formula CC-[(B)q-(A)pQ]n. 5. The method of embodiment 2, wherein the photopolymerizable composition comprises a first photopolymerizable macromer component that is biaxial and a second photopolymerizable macromer component that is multiaxial but not biaxial, e.g., triaxial and tetraaxial. 6. The method of embodiment 2, wherein the photopolymerizable composition comprises a first photopolymerizable macromer component that is triaxial and a second photopolymerizable macromer component that is multiaxial but not triaxial, e.g., biaxial and tetraaxial. 7. The method of embodiment 2, wherein the photopolymerizable composition comprises a first photopolymerizable macromer component that is tetraaxial and a second photopolymerizable macromer component that is multiaxial but not tetraaxial, e.g., biaxial and triaxial. 8. The method of any of embodiments 1-7, further comprising a light reflector component to increase the rate of polymerization at the surface of the composition where light contacts the photopolymerizable composition compared to the same photopolymerizable composition without the light reflector component. 9. The method of any of embodiments 1-8, wherein the photoinitiator components have a total concentration of less than 1% by weight. 10. The method of any of embodiments 1-9, wherein the photopolymerizable composition further comprises a reactive diluent. 11. The method of any of embodiments 1-10, wherein the photopolymerizable composition further comprises a non-reactive diluent. 12. The method of any of embodiments 1-11, wherein the photopolymerizable composition further comprises a stabilizer, which is optionally a free radical stabilizer. 13. The method of any of embodiments 1-12, further comprising a secondary curing step comprising curing the printed article. 14. The method of any of embodiments 1-13, wherein the wavelength of light used in the photopolymerization is from 10 nm to 700 nm. 15. The method of any of embodiments 1-14, wherein the printed article is biodegradable and non-toxic to subjects exposed to the printed article. 16. A polymer formed by the method of any one of embodiments 1-15. 17. An article made by the method of any one of embodiments 1-15. 18. The article of embodiment 17, wherein the article is a medical device. 19. The article of embodiment 17, wherein the article is at least a part of a medical device. 20. The article of embodiment 17, wherein the article is porous. 21. The article of embodiment 17, wherein the article is biodegradable under physiological conditions. 22. The article of embodiment 17, wherein the article completely degrades under physiological conditions within a period of about 3 days to about 5 years. 23. The article of embodiment 17, wherein the article is not biodegradable. 24. The article of embodiment 17, wherein the article is drug-eluting.

[0047] The invention has been described broadly and generically herein. Each narrower species or subgroup falling within the generic disclosure also forms part of the invention. This is understood to include a generic description with a condition or negative limitation that excludes any subject matter of the invention from that genus, regardless of whether the omitted portion is specifically recited herein. As used in this specification and the appended claims, the singular forms "a," "an," and "the" include the plural unless the context clearly dictates otherwise; "X and / or Y" means "X" or "Y," or both "X" and "Y," and "plural" after a noun includes both the plural and singular forms of that noun. Furthermore, when features or aspects of the invention are described in the form of a Markush group, it is intended, and will be understood by those skilled in the art, that the invention encompasses and is described in terms of any individual element or subelement of the Markush group. Applicant also reserves the right to amend the application or claims to specifically refer to any individual element and any subelement of the Markush group.

[0048] The following examples are offered by way of illustration and not by way of limitation. Chemicals were obtained from commercial sources, such as MilliporeSigma (St. Louis, MO, USA). [Example]

[0049] Example 1 Preparation of Compounds of the Disclosure Generally Described as Formula CC-[arm-OH] Table 1 identifies 16 prepolymers, individually labeled as BCPE1 through BCPE16, generally described as having or including compounds of the general formula CC-[arm-OH] in accordance with the present disclosure. The term arm-OH refers to an arm that terminates in a hydroxy group (OH), i.e., has a hydroxy end group. When a prepolymer comprises a compound having the formula CC-[(A)-(B)], i.e., the arms are formed from residues of monomers from Group A (any one or more of trimethylene carbonate and ε-caprolactone) proximal (adjacent) to the central core and residues of monomers from Group B (one or more of glycolide, lactide, and p-dioxanone) distal (furthest) from the central core, such prepolymers can be prepared by reacting a functionalized central core (also referred to herein as an initiator) with one or more monomers from Group A, followed by reacting the reaction product (referred to herein as a prepolymer precursor) with one or more monomers from Group B. The resulting central core is attached to one or more arms, each hydroxy-terminated and having the formula -(A)-(B)-OH. The preparation of such a prepolymer is illustrated in Example 1A below, where the central core is trifunctional and the functionalized central core / initiator is provided by trimethylolpropane.

[0050] Example 1A - Preparation of Triaxial BCPE6 Prepolymer Trimethylene carbonate (1.4 mol) and ε-caprolactone (1.4 mol) were reacted with trimethylolpropane (0.6 mol) as an initiator and tin octoate (7.0 × 10 -5 The copolymerization was carried out at 130 °C for 72 hours to obtain a prepolymer precursor. Glycolide (1.1 mol) and additional stannous octoate (2.1 × 10 -4 (mol) was compounded with the prepolymer precursor at 160°C for 3 hours to obtain a prepolymer having polyglycolide grafts at the ends of the prepolymer precursor. The amorphous liquid prepolymer thus obtained was devolatilized and 1 H NMR spectroscopy, fluid measurement (shear rate 105s -1It was characterized by its viscosity at 17,300 mPa·s, differential scanning calorimetry (Tg=-45°C), and gel permeation chromatography (Mn=1884 Da, PDI=1.80). When a prepolymer contains a compound having the formula CC-[(B)-(A)], i.e., where residues of monomers from Group B (glycolide, lactide, and p-dioxanone) are proximal (adjacent) to the central core and residues of monomers from Group A (trimethylene carbonate and caprolactone) are distal (furthest) from the central core, such prepolymers can be prepared by reacting a functionalized central core with one or more monomers from Group B and subsequently reacting the reaction product with one or more monomers from Group A. The resulting central core is attached to one or more arms, each hydroxy-terminated and having the formula -(B)-(A)-OH. The preparation of such a prepolymer is illustrated in Example 1B below, where the central core is trifunctional and the functionalized central core is provided by trimethylolpropane.

[0051] Example 1B - Preparation of Triaxial BCPE4 Prepolymer In the first step, glycolide (1.1 mol) was reacted with trimethylolpropane (0.6 mol) as an initiator and tin octoate (7 × 10 -5 After the first step was completed, a mixture of equimolar amounts of trimethylene carbonate (1.4 mol) and ε-caprolactone (1.4 mol) was added to stannous octoate (2×10 -4 The resulting amorphous liquid prepolymer was copolymerized at the end of the prepolymer precursor by further adding 20 moles of methyl methyl acrylate and reacting at 130°C for 72 hours. 1 H NMR spectroscopy, fluid measurement (shear rate 105s -1 It was characterized by its viscosity at 17,300 mPa·s, differential scanning calorimetry (Tg=-45°C), and gel permeation chromatography (Mn=1909 Da, PDI=1.83). Following the procedures outlined in Examples 1A and 1B, additional polyester prepolymers were synthesized as shown in Table 1. All linear samples were synthesized using 1,3-propanediol as the difunctional initiator, all trifunctional prepolymers were prepared using trimethylolpropane, and the four-arm block copolyester compositions were initiated with pentaerythritol as the tetrafunctional initiator. In Table 1, M / I represents the total number of moles of monomers (M) used to prepare the arms of each copolyester shown in Table 1 divided by the number of moles of initiator (also referred to as the functionalized central core) (I). Also in Table 1, M / C represents the total number of moles of monomers (M) used to prepare the arms of each copolyester prepolymer shown in Table 1 divided by the number of moles of catalyst (C). Each of the prepolymers in Table 1 contains a B region, which can be either proximal to the central core (in which case the location of the B region is identified as being in the middle of the prepolymer) or distal to the central core (in which case the location of the B region is identified as being at the end of the prepolymer, in which case the B region terminates in a hydroxy group).

[0052] Selected molecular weight results obtained by gel permeation chromatography (GPC) for selected prepolymers prepared as shown in Example 1 are shown in Table 2. In Table 2, Mn represents number average molecular weight, Mw represents weight average molecular weight, PDI represents polydispersity (i.e., Mw / Mn), and Da represents Daltons.

[0053] [Table 1] [Table 2]

[0054] Example 2 Preparation of Methacrylated Compounds of the Disclosure, Generally Described as Formula CC-[Arm-Q] Table 3 identifies eight Q-functionalized prepolymers, individually labeled BCPE4Q through BCPE7Q and BCPE9Q through BCPE12, generally described as having or including compounds of the general formula CC-[arm-Q] according to the present disclosure. The designation arm-Q refers to an arm that terminates in a photoreactive group (Q), such as an acrylate or methacrylate group. The methacrylated prepolymers in Table 3 are prepared from the corresponding prepolymers in Table 1, i.e., BCPE4Q is prepared from BCPE4, BCPE5Q is prepared from BCPE5, etc.

[0055] Methacrylation of BCPE6 to form BCPE6Q BCPE6 prepolymer (0.131 mol) was reacted with excess methacrylic anhydride in the presence of 3-tert-2-butyl-4-hydroxyanisole (6.724 × 10 mol) at 120°C for 24 hours. Residual methacrylic anhydride and methacrylic acid by-products were removed from the cured polymer using a rotary evaporator. The resulting amorphous liquid polymer was 1 The BCPE formulations were characterized by H NMR spectroscopy, rheometry (viscosity 16,400 mPa s at a shear rate of 10 s), differential scanning calorimetry (Tg = -38 °C), and gel permeation chromatography (Mn = 2162 Da, PDI = 1.75). Each BCPE formulation was methacrylated according to the procedure outlined above. A summary of the composition and molecular weight results is shown in Table 3, and the kinematic viscosity is reported in Table 4. In Table 3, for BCPE5Q, the 40.15 in the TMC column is the total mole % TMC plus 1,3-propanediol used to make BCPE5Q.

[0056] [Table 3] [Table 4]

[0057] Block structure analysis of methacrylated BCPE compounds Proton NMR spectra of methacrylated BCPE polymers were measured in deuterated dichloromethane (20 mg / ml) solutions using a JEOL 300 MHz NMR spectrometer and analyzed using JEOL Delta software. The spectra of the triaxial BCPE prepolymer are shown in Figures 1A, 1B, 1C, and 1D, while the spectra of the linear BCPE prepolymer are shown in Figures 2A, 2B, 2C, and 2D. Peaks associated with the alkenyl protons of the methacrylate groups appear at δ values ​​between 5.5 and 6.3 ppm in the spectrum. Depending on the monomer residue adjacent to the methacrylate group, the position of the proton peaks shifts slightly. Methacrylate groups adjacent to glycolide residues (also referred to herein as glycolide-related) appear further downfield than the corresponding methacrylates adjacent to either TMC or caprolactone residues (also referred to herein as TMC- or caprolactone-related). The peak area of ​​the glycolide-related methacrylate protons, and therefore the number of methacrylate groups adjacent to a glycolide residue, is higher for BCPE6Q and BCPE7Q, which have terminal grafts of glycolide residues, than for BCPE4Q and BCPE5Q, which have a glycolide residue central block. The area of ​​the glycolide-related methacrylate peak increases progressively with increasing glycolide residues in the prepolymer, while the methacrylate peaks associated with TMC and caprolactone disappear to negligible levels when the proportion of glycolide residues in the polymer is 50% or higher.

[0058] Example 3 Preparation of films by photopolymerization of BCPE6Q 15 g of methacrylated BCPE6 (BCPE6Q) was weighed and mixed with 0.5 wt% 2,4,6-trimethylbenzoylphenylphosphinate (i.e., Irgacrure® TPO-L). This mixture was cast between two UV-transparent sheets with shims allowing a film thickness of 0.75 mm. Using a Blak-ray™ B-100, a 365 nm 100 W light source was applied approximately 13 mm from the mold for 5 minutes to obtain the crosslinked film BCPE6X. Following essentially the same photopolymerization procedure, BCPE1Q, BCPE4Q, BCPE5Q, BCPE7Q, BCPE9Q, and BCPE10Q were used as starting materials to obtain the corresponding crosslinked films BCPE1X, BCPE4X, BCPE5X, BCPE7X, BCPE9X, and BCPE10X. The properties of the resulting crosslinked polymer films were evaluated by differential scanning calorimetry (Tg=-13°C) and mechanical testing. Each BCPE film was tested according to ASTM D882. Briefly, thin films were cut to a length of 75 mm and a width of 7.5 mm. Samples were tested between fixed grips on an MTS Synergie 200 electromechanical mechanical tester at room temperature (approximately 21°C). The test gauge length was 25.4 mm, and the crosshead speed was 2.5 mm / min. Results for selected formulations are shown in Table 5. [Table 5]

[0059] Example 4 Accelerated degradation of polymerized 3DP films Films produced under the conditions described in Example 3 were cut into rectangles measuring 75 mm (length) x 7.5 mm (width) x 0.75 mm (thickness). Each sample was weighed, and mechanical properties were evaluated as outlined in Example 3. The samples were then placed in 15 ml of 0.1 M phosphate buffer at pH 7.4. The rectangular samples were conditioned at 50°C for 1, 3, 7, 14, 21, and 56 days. At each time point, the specimens were blotted dry and weighed. The samples were then dried under vacuum until a constant mass was reached. The dry mass of each specimen was measured, and the intact samples were analyzed for mechanical properties as described in Example 3. Figures 3-6 report the strength loss, mass loss, and moisture content results for selected formulations. The increase in glycolide-derived composition between BCPE4X and BCPE6X to BCPE9X resulted in an increase in the compressive modulus of the films, which may be attributed to a shift in the glass transition temperature of the materials. Within the group of films prepared from linear prepolymers, the modulus of BCPE7X, with glycolide-derived end grafts, is significantly higher than that of BCPE5X, with glycolide-derived central blocks. For films from linear prepolymers, BCPE7X (glycolide-derived end regions) films also exhibited faster strength loss up to 14 days compared with BCPE5X (glycolide-derived central region) films. However, BCPE5X (glycolide-derived central region) films exhibited higher strength loss at 21 days, the last testable time point. Within the group of films prepared from triaxial prepolymers, the modulus of BCPE6X, which has glycolide-derived end grafts, is not significantly greater than that of BCPE4X, which has glycolide-derived central blocks. It is also noteworthy that BCPE6X (glycolide-derived end regions) films exhibited faster strength loss than BCPE4X (glycolide-derived central regions) films. BCPE6X films became unstable after 7 days, whereas BCPE4X films endured for an additional 7 days. Comparing the mass loss and water content of BCPE4X and BCPE6X films, BCPE4X exhibited a greater mass loss over 56 days than BCPE6X. A larger mass loss would predict a higher water content for that sample, but this was not the case. If caprolactone / TMC were reacted strictly on the end grafts, a larger mass loss would unexpectedly be achieved at lower swelling, i.e., lower water content. In both formulations, premature degradation may be occurring at the glycolide repeat unit. As described in Example 2, when TMC / caprolactone end grafts are used, a greater amount of TMC / caprolactone is located immediately adjacent to the methacrylate group. In this case, the hydrophilicity of the polymer backbone is reduced compared to when glycolide-derived residues are located next to the methacrylate group. The same results were observed when comparing films BCPE5X and BCPE7X, derived from linear prepolymers BCPE5 and BCPE7, respectively. It is clear that the block structure or position of the monomer residues has a direct impact on the resulting properties. If a relatively fast-absorbing monomer residue (e.g., derived from glycolide) is located at the end of a prepolymer arm, the corresponding crosslinked polymer is expected to have a faster strength loss profile compared to when glycolide residues are used to form the central block. If a relatively fast-absorbing monomer residue (e.g., glycolide residue) is located in the center of the prepolymer, a lower water content is observed with a higher mass loss, which can be advantageous.

[0060] Example 5 Preparation of Thiolated Compounds of the Disclosure, Generally Described as Formula CC-[Arm-Q] A 500 mL three-neck round-bottom flask equipped with a mechanical stirrer and an addition funnel was charged with BCPE6 (51.3 g; 0.0665 mol; see Table 1), thiolactic acid (17.243 mL; 20.623 g; 0.1943 mol), and dichloromethane (DCM) (200 mL) under a nitrogen atmosphere. The contents of the reaction vessel were stirred at 200 rpm, and the reaction vessel was cooled using an ice bath. Separately, N,N'-dicyclohexylcarbodiimide (DCC) (44.5 g, 0.2157 mol) was dissolved in 200 mL of DCM. The DCC in DCM solution was then added dropwise to the reaction vessel over 30 min using the addition funnel. After the addition of the DCC / DCM solution was complete, the ice bath was removed. 4-Dimethylaminopyridine (DMAP) (2.366 g; 0.0193 mol) was added to the reaction vessel using a powder funnel. The reaction mixture was stirred at room temperature under a nitrogen atmosphere for 72 hours. DCM evaporated during the reaction, so DCM was replenished. After 72 hours, the reaction mixture was suction filtered. The filtrate was washed with 2 x 100 mL of 0.25 M HCl and 1 x 100 mL of deionized (DI) water. The extracted organic phase was dried over activated molecular sieves (3 Å) for 18 hours and then suction filtered. The solvent was removed under vacuum using a rotary evaporator to obtain a liquid polymer product (BCPE6-TLA). The amorphous liquid polymer thus obtained was 1 H NMR spectroscopy, fluid measurements (shear rate 99s -1 The polymer was characterized by viscosity at 7690°C (Mn=1952 Da, PDI=1.62) and gel permeation chromatography.

[0061] Example 6 Photopolymerization of Thiolated Polymers of the Present Disclosure The thiolated BCPE6 polymer (BCPE6-TLA) from Example 5 was mixed with 10% (w / w) phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO) photoinitiator and photocured using a Dymax Bluewave 200 UV Light-Curing Spot Lamp System at an intensity of 60 mW / cm. 2The polymer / BAPO mixtures were exposed to UV light for 0-30 seconds. The light-exposed samples were analyzed using rheometry and gel permeation chromatography. The analysis revealed a trend toward increasing both viscosity and molecular weight as the polymer / BAPO mixtures were exposed to UV light for increased time.

[0062] Example 7 Preparation of Thiolated Compounds of the Disclosure, Generally Described as Formula CC-[Arm-Q] Polymers bearing hydroxy groups can be capped with moieties that replace the hydroxy groups with carboxylic acid groups. The carboxylic acid groups can then be substituted with thiol-containing moieties via amide or ester linkages, depending on the functional unit of the substituent used for attachment. For example, the hydroxyl end groups of a BCPE prepolymer (see, e.g., Table 1) can be reacted with succinic anhydride to form a succinate intermediate (BCPE-SA), which then reacts with the amine group present in cysteine ​​to give a product bearing a terminal free thiol group (BCPE6-SA-Cys). This approach is exemplified by this example. Part 1 - Formation of BCPE6-SA: A 250 mL three-neck round-bottom flask was charged with BCPE6 (48.9 g; 0.0633 mol, Table 1). The system was placed under vacuum (<0.5 torr) at 40°C for 18 hours to dry the prepolymer. After 18 hours, the system was purged with nitrogen and succinic anhydride (19.0 g; 0.1900 mol) was added to the reaction vessel. The reaction mixture was stirred at 50 rpm at 120°C for 24 hours. The resulting polymer was cooled to room temperature and devolatilized on a rotary evaporator at room temperature for 18 hours and then at 110°C for 24 hours to remove residual monomer. The structure of the resulting transparent amorphous polymer product was determined as follows: 1 This was confirmed using 1 H NMR. Part 2—Formation of BCPE6-SA-Cys: A 100 mL two-neck flask was charged with BCPE6-SA (10.1 g; 0.0093 mol), L-cysteine ​​(3.39 g; 0.0280 mol), and dichloromethane (DCM) (30 mL). The reactants were stirred at 200 rpm under a nitrogen atmosphere. Separately, N,N'-dicyclohexylcarbodiimide (DCC) (6.35 g, 0.0307 mol) was dissolved in 10 mL of DCM. An ice bath was placed around the reaction vessel, and the DCC / DCM solution was added dropwise. After the addition of the DCC / DCM solution was complete, the ice bath was removed, and the reactants were stirred at room temperature under a nitrogen atmosphere for 72 hours. After 72 hours, the reaction mixture was diluted with 50 mL of DCM and suction filtered. The filtrate was washed with 2 x 50 mL of 0.25 M HCl and 1 x 50 mL of DI water. The extracted organic phase was dried over activated molecular sieves (3 Å) for 18 hours and then suction filtered. The solvent was removed under vacuum on a rotary evaporator to give the waxy polymer product (BCPE6-SA-Cys). The structure is shown below. 1 Confirmed by 1 H NMR spectroscopy.

[0063] Example 8 Printing of SLA compounded articles Three-dimensional objects were created using a rectangular parallelepiped Solidworks® computer program (Solidworks Corp.). The three-dimensional object file was converted to an STL file. The formulation used for this printing was 41.6% by weight BCPE5, 41.6% by weight PEGDA, 0.2% by weight Irgacure® TPO-L, and 16.6% by weight polyglycolide microparticles. This formulation was added to the ink bed of a B9 Creator v1.2 SLA printer. The object was printed with a layer thickness of 30 μm, using an exposure time of 6 seconds for the first two layers and 3 seconds for subsequent layers. The light intensity of the SLA printer was 3 mW / cm as measured by a UVA detector. 2 It was.

[0064] All references disclosed in the specification, including patent applications and non-patent literature, are hereby incorporated by reference in their entirety, as if each were individually incorporated. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. Further, unless specifically defined herein, it is to be understood that terms used herein are to be given their conventional meaning as known in the relevant art.

[0065] Throughout this specification, references to "one embodiment" or "an embodiment" and variations thereof mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Also, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural, i.e., one or more, references unless the context clearly dictates otherwise. For example, "a" macromer refers to "one or more" macromers, which can also be expressed as "at least one" macromer. The conjunctions "and" and "or" are generally used in their broadest sense, including "and / or," unless the content and context clearly dictate otherwise, as the case may be. The use of alternatives (e.g., "or") should be understood to mean either one, both, or any combination thereof of the alternatives. Additionally, when referred to herein as "and / or," the "and" and "or" constructs are intended to encompass embodiments that include all of the associated items or concepts, as well as one or more other alternative embodiments that include fewer than all of the associated items or concepts. Unless the context otherwise requires, throughout this specification and claims, the word "comprise" and its cognates and variations, such as "including" and "having," and variations thereof, such as "including," are to be construed in an open, inclusive sense, e.g., "including, but not limited to." The term "consisting essentially of" limits the claim to the specified materials or steps, or those that do not materially affect the basic and novel characteristics of the claimed invention. When something is "selected from" two or more specified options, it refers to selecting one, two, or all of the specified options. For example, if a monomer (where "a" monomer, as defined above, refers to at least one monomer) is selected from TMC and CAP, the disclosure selects TMC or CAP, or a combination of CAP and TMC. Furthermore, when a compound, composition, method, etc. has a recited feature, that feature may be supplemented by additional features. For example, in a method having a recited feature, if the recited feature is selecting a monomer from TMC and CAP, the selected monomer(s) necessarily includes at least one of TMC and CAP, but may also include one or more other monomers, i.e., unrecited monomers.

[0066] Any headings used herein are merely utilized for the convenience of the reader and should not be construed as limiting the scope of the invention or the claims in any way. Accordingly, the headings and abstracts provided herein are merely for convenience and do not interpret the scope or meaning of the embodiments. Where a range of values ​​is given herein, it is understood that each intervening value between the upper and lower limit of that range, and any other stated or intervening value within that range, to the tenth of the unit of the lower limit, unless the context clearly indicates otherwise, is encompassed within the disclosure and claims. The upper and lower limits of these smaller ranges may independently be included in the subrange, and any specifically excluded limit in the stated range is also included. Where the stated range includes one or both of these limits, ranges excluding either or both of those limits are also included in the invention. For example, any concentration range, percentage range, ratio range, or integer range set forth herein should be understood to include any integer within the recited range, and fractions thereof, where appropriate (such as tenths and hundredths of integers), unless otherwise specified. Also, any numerical range recited herein relating to any physical characteristic, such as polymer subunits, size, or thickness, should be understood to include any integer within the recited range, unless otherwise specified. As used herein, the term "about" means ±20% of the stated range, value, or structure, unless otherwise specified.

[0067] All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications, and non-patent publications referenced herein and / or listed in the Application Data Sheet are incorporated herein by reference in their entirety. Such documents may be incorporated by reference, for example, for the purpose of describing and disclosing the materials and methodologies that are described in the publications and that may be used in connection with the invention. The publications mentioned above and throughout the text are provided solely for the purpose of illustrating their disclosure prior to the filing date of the present application. Nothing herein should be construed as an admission that the inventors are not entitled to antedate any cited reference by virtue of prior invention. All patents, publications, scientific articles, websites, and other literature and materials referenced or described in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains, and each such referenced publication and material is incorporated by reference to the same extent as if it were individually incorporated by reference in its entirety or as if set forth in its entirety herein. Applicant reserves the right to physically incorporate into this specification any and all materials and information from any such patents, publications, scientific articles, websites, electronically available information, and other referenced materials or literature. Furthermore, the written description portion of this patent encompasses all claims. Furthermore, all claims, including all original claims and all claims from any and all priority documents, are incorporated by reference in their entirety into the written description herein. Applicant also reserves the right to physically incorporate any and all such claims into the written description portion or any other portion of this application. Thus, for example, in no event will this patent be construed as unjustifiably failing to provide a written description for a claim based on an assertion that the claim language is not recited in the exact words in the written description portion of this patent.

[0068] The following are some additional exemplary embodiments provided by the present disclosure: 1) A photopolymerizable compound comprising a polyaxial central core (CC) and two to four arms of the formula (A)-(B) or (B)-(A) extending from the central core, at least one of the arms containing a photoreactive functional group (Q), wherein (A) is a ring-opening polymerization product from a monomer selected from trimethylene carbonate (T) and ε-caprolactone (C), while (B) is a ring-opening polymerization product from a monomer selected from glycolide, lactide, and p-dioxanone. 2) A photocurable composition comprising one or more photopolymerizable compounds of embodiment 1, and optionally further comprising a photopolymerization initiator. 3) a photoreactive multiaxial macromer comprising a central core (CC) and two to four arms extending from the central core, at least one of the arms comprising a photoreactive functional group (Q) and a block copolymer comprising a block A and a block B; a. Block A comprises residues formed from at least one of trimethylene carbonate (TMC) and ε-caprolactone (CAP); and b. a block copolymer, wherein block B comprises residues formed from at least one of glycolide, lactide, and p-dioxanone; 4) A photocurable composition comprising one or more macromers of embodiment 3, and optionally further comprising a photoinitiator. 5) A prepolymer of the photopolymerizable compound of embodiment 1, wherein the central core (CC) is attached to (A) of one or more arms of formula (A)-(B), and (B) comprises a hydroxy end group. 6) A prepolymer of the photopolymerizable compound of embodiment 1, wherein the central core (CC) is bonded to one or more arms (B) of the formula (B)-(A), and (A) has a hydroxy end group. Thus, the prepolymer comprises a multiaxial central core (CC) and from two to four arms of the formula (A)-(B) or (B)-(A) extending from the central core, at least one of the arms having a hydroxy end group (i.e., a hydroxy group at the end of the arm furthest from the central core), and wherein (A) is a ring-opening polymerization product from a monomer selected from trimethylene carbonate (T) and ε-caprolactone (C), while (B) is a ring-opening polymerization product from a monomer selected from glycolide, lactide, and p-dioxanone. 7) The compound of embodiment 1, which is reactive when exposed to UV radiation. 8) The compound of embodiment 1, comprising the structure CC-[ABQ]2. 9) The compound of embodiment 1, comprising the structure CC-[ABQ]3. 10) The compound of embodiment 1, comprising the structure CC-[ABQ]4. 11) The compound of embodiment 1, comprising the structure CC-[BAQ]2. 12) The compound of embodiment 1, comprising the structure CC-[BAQ]3. 13) The compound of embodiment 1, comprising the structure CC-[BAQ]4. 14) The composition of any of embodiments 1-7, wherein the macromer has four arms, a molecular weight of less than 40,000 g / mol, and is a solid at room temperature. 15) The composition of any of embodiments 1-7, wherein the macromer has three arms, a molecular weight of less than 5,000 g / mol, and is a liquid at room temperature. 16) The composition of any of embodiments 1-7, wherein the macromer has two arms, a molecular weight of less than 5,000 g / mol, and is a liquid at room temperature. 17) The composition of any of embodiments 1-16, further comprising CC-[ABQ]n, where n is 1. 18) The composition of any of embodiments 1-16, further comprising at least one of CC-Q, CC-AQ, and CC-BQ. 19) The composition of any of embodiments 1-16, further comprising at least one of QA, QB, and Q-CC. 20) The composition of any of embodiments 1-19, wherein Q comprises a thiol group. 21) The composition of any of embodiments 1-19, wherein Q comprises a vinyl group. 22) The composition of embodiment 21, wherein the vinyl group is an acrylate or methacrylate group. 23) The composition of any of embodiments 1-22, wherein block A comprises a residue formed from TMC. 24) The composition of any of embodiments 1-22, wherein block A comprises a residue formed from CAP. 25) The composition of any of embodiments 1-22, wherein block A comprises residues formed from both TMC and CAP. 26) The composition of any of embodiments 1-22, wherein at least 90% of the residues of block A are formed from TMC or CAP. 27) The composition of any of embodiments 1-22, wherein the macromer comprises 2-45 residues formed from TMC. 28) The composition of any of embodiments 1-22, wherein the macromer comprises 2-15 residues formed from TMC. 29) The composition of any of embodiments 1-22, wherein the macromer comprises 2-10 residues formed from TMC. 30) The composition of any of embodiments 1-26, wherein block A has a molecular weight of 102 to 2500 g / mol. 31) The composition of any of embodiments 1-26, wherein block A has a molecular weight of 102 to 1000 g / mol. 32) The composition of any of embodiments 1-26, wherein block A has a molecular weight of 102 to 900 g / mol. 33) The composition of any of embodiments 1-26, wherein each A block comprises 2-45 monomer residues. 34) The composition of any of embodiments 1-26, wherein each A block comprises 2-15 monomer residues. 35) The composition of any of embodiments 1-26, wherein each A block comprises 2-10 monomer residues. 36) The composition of any of embodiments 1-35, wherein each B block comprises 2-45 monomer residues. 37) The composition of any of embodiments 1-35, wherein each B block comprises 2-15 monomer residues. 38) The composition of any of embodiments 1-35, wherein each B block comprises 2-15 monomer residues. 39) The composition of any of embodiments 1-36, wherein the block copolymer has a molecular weight of less than 40,000 g / mol. 40) The composition of any of embodiments 1-36, wherein the block copolymer has a molecular weight of less than 25,000 g / mol. 41) The composition of any of embodiments 1-36, wherein the block copolymer has a molecular weight of less than 10,000 g / mol. 42) The composition of any of embodiments 1-41, having a viscosity of less than 50,000 mPa·s at room temperature. 43) The composition of any of embodiments 1-41, having a viscosity of less than 30,000 mPa·s at room temperature. 44) The composition of any one of embodiments 1-41, having a viscosity of less than 20,000 mPa·s at room temperature. 45) The composition of any of embodiments 1-44, further comprising a photoinitiator. 46) The composition of any of embodiments 1-45, further comprising a reactive diluent such as PEG-diacrylate (PEG-DA).

[0069] Other embodiments are within the scope of the following claims. The claims will be construed according to law. However, notwithstanding any assertion or recognition that any claim, or portion thereof, is easy or difficult to interpret, modifying or amending any claim, or portion thereof, during the prosecution of the application(s) resulting in a patent shall not in any way be construed as a waiver of any and all equivalents of this patent that do not form part of the prior art. The patent should not be construed as limited to the particular examples or embodiments or methods specifically and / or expressly disclosed herein. In no event shall the patent be construed as limited by statements made by the examiner or any other officer or employee of the Patent and Trademark Office unless such statements are detailed and are in the absence of a qualification or reservation expressly adopted in the applicant's reply brief. In general, in the following claims, the terms used should not be construed as limiting the scope of the claims to the specific embodiments disclosed in the specification and claims, but should be construed as embracing all possible embodiments, along with the full scope of equivalents within the scope of such claims. Accordingly, the scope of the claims is not limited by the disclosure.

Claims

1. 1. A photopolymerizable compound comprising a polyaxial central core (CC) and two to four arms of the formula (A)-(B) or (B)-(A) extending from said central core, wherein at least one of said arms comprises a photoreactive functional group (Q), wherein (A) is a ring-opening polymerization product from a monomer selected from trimethylene carbonate (T) and ε-caprolactone (C), while (B) is a ring-opening polymerization product from a monomer selected from glycolide, lactide, and p-dioxanone.

2. A photocurable composition comprising one or more photopolymerizable compounds according to claim 1 and a photopolymerization initiator.

3. A photoreactive multiaxial macromer comprising a central core (CC) and two to four arms extending from said central core, at least one of said arms comprising a photoreactive functional group (Q) and a block copolymer comprising a block A and a block B; a. Block A comprises residues formed from at least one of trimethylene carbonate (TMC) and ε-caprolactone (CAP); and b. Block B comprises residues formed from at least one of glycolide, lactide, and p-dioxanone; Photoreactive multiaxial macromer.

4. A photocurable composition comprising one or more macromers according to claim 3 and a photoinitiator.

5. CC-[A-B-Q] 2 , CC-[A-B-Q] 3 , CC-[A-B-Q] 4 , CC-[B-A-Q] 2 , CC-[B-A-Q] 3 , CC-[B-A-Q] 4 2. The compound of claim 1, comprising a structure selected from the group:

6. 3. The composition of claim 2, further comprising a compound of formula CC-[ABQ]n, wherein n is 1.

7. 3. The composition of claim 2, further comprising at least one compound of a formula selected from CC-Q, CC-AQ, and CC-BQ.

8. 3. The composition of claim 2, further comprising at least one compound of a formula selected from QA, QB, and QCC.

9. 2. The compound of claim 1, wherein Q comprises a thiol group.

10. 2. The compound of claim 1, wherein Q comprises a vinyl group, such as an acrylate or methacrylate group.

11. 2. The compound of claim 1, wherein block A comprises a residue that is a polymerization product of TMC and / or CAP.

12. 2. The compound of claim 1, wherein at least 90% of the residues of block A are the polymerization product of TMC or CAP.

13. The compound of claim 1, wherein the macromer comprises 2 to 45 residues formed from TMC.

14. 2. The compound according to claim 1, wherein block A has a molecular weight of 102 to 2500 g / mol.

15. The compound of claim 1 , wherein each A block comprises 2 to 45 monomer residues.

16. The compound of claim 1 , wherein each B block comprises 2 to 45 monomer residues.

17. 10. The compound of claim 1 having a molecular weight of less than 40,000 g / mol.

18. 3. The composition of claim 2 having a viscosity of less than 50,000 mPa·s at room temperature.

19. The composition of claim 2 further comprising a reactive diluent such as PEG-diacrylate (PEG-DA).

20. A method of stereolithographic printing an article comprising exposing a photopolymerizable composition disclosed herein, such as the composition of claim 1, to light for a period of time.

21. a) i. at least one photopolymerizable macromer component; iii. at least one photoinitiator component; exposing a photopolymerizable composition comprising: b) forming a printed article comprising a polymerized form of said macromer component; 1. A method of photopolymerization printing an article, comprising: The photopolymerizable macromer component comprises a central core (CC) and a plurality of arms extending from the central core, all or substantially all of the arms terminating in a photopolymerizable group (Q); each arm is formed by polymerization of monomers selected from two groups, designated Group A and Group B; resulting in Region A and Region B, respectively, within the arm, wherein Region A represents the polymerization product of one or more monomers including, and optionally selected only from, trimethylene carbonate (T) and caprolactone (C), and Region B represents the polymerization product of one or more monomers including, and optionally selected only from, glycolide (G), lactide (L), and p-dioxanone (D). method.

22. 1. A compound comprising a polyaxial central core (CC) and two to four arms of the formula (A)-(B) or (B)-(A) extending from said central core, at least one of said arms comprising a terminal hydroxy group, wherein (A) is a ring-opening polymerization product from monomers selected from trimethylene carbonate (T) and ε-caprolactone (C), while (B) is a ring-opening polymerization product from monomers selected from glycolide, lactide, and p-dioxanone.

23. a multiaxial macromer comprising a central core (CC) and two to four arms extending from said central core, at least one of said arms comprising a terminal hydroxy group and a block copolymer comprising a block A and a block B; a. Block A comprises residues formed from at least one of trimethylene carbonate (TMC) and ε-caprolactone (CAP); and b. Block B comprises residues formed from at least one of glycolide, lactide, and p-dioxanone; Multiaxial macromer.

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