Compositions for time and spatially controlled delivery of therapeutic agents

Abstract

The invention relates to a composition configured for time and spatially controlled delivery of two or more therapeutic agents to a damaged tissue, characterized in that the composition is in a solid and planar form and comprises a basal layer, two or more segments attached to the basal layer and two or more therapeutic agents, wherein the two or more segments are horizontally arranged on the basal layer and separated by a blocking layer, wherein the two or more segments comprise one or more polymer layers, wherein a first polymer layer is attached to the basal layer and one or more further polymer layers are vertically stacked on to the first polymer layer, and each of the two or more segments comprises one or more of the therapeutic agents in at least one polymer layer. Further the invention relates to the composition for use in the treatment of a medical condition associated with a healing disorder.

Description

[0001] COMPOSITIONS FOR TIME AND SPATIALLY CONTROLLED DELIVERY OF THERAPEUTIC AGENTS

[0002] DESCRIPTION

[0003] The invention is in the field of pharmaceutical compositions for controlled release of therapeutic agents, in particular for controlled release of therapeutic agents to damaged tissue of a subject.

[0004] The invention relates to a composition configured for time and spatially controlled delivery of two or more therapeutic agents to a damaged tissue of a subject, characterized in that the composition is in a solid and planar form and comprises a basal layer, two or more segments attached to the basal layer and two or more therapeutic agents, wherein the two or more segments are horizontally arranged on the basal layer and separated by a blocking layer, wherein the two or more segments comprise one or more polymer layers, wherein a first polymer layer is attached to the basal layer and one or more further polymer layers are vertically stacked on to the first polymer layer, and each of the two or more segments comprises one or more of the therapeutic agents in at least one polymer layer. Further the invention relates to the composition for use in the treatment of a medical condition associated with a healing disorder.

[0005] BACKGROUND OF THE INVENTION

[0006] In acute and chronic spinal cord injuries such as after traumatic lesions, a complex pathophysiology leads to a very low regenerative capacity of the nerve fibers in the spinal cord. In most cases, the resulting paralyses persist and, depending on the site of injury, patients are dependent on a wheelchair or completely bedridden for the rest of their lives.

[0007] The underlying pathophysiology of spinal cord injury is complex in terms of time and space:

[0008] In the acute phase of spinal cord injury (< 48 h after injury), the mechanical force leads to compression or transection of the myelon due to disruption and dislocalisation of the spinal column. This results in the localized destruction of neurons, injury to blood vessels and impairment of the blood-spinal cord barrier. The influx of inflammatory cells leads to increased swelling of the spinal cord with aggravated compression, which can spread beyond the originally affected segment. In the subacute phase (48 h - 14 days after injury), ischemia and excitotoxicity lead to a loss of intra- and extracellular homeostasis. Neurotransmitters such as glutamate released due to cell death lead to overactivation of excitatory receptors; together with a lack of ATP-dependent ion pumps, this leads to increased excitotoxicity and cell death. The ischemia can persist for days to weeks due to the loss of autoregulation of the blood vessels of the spinal cord and increase neuronal and glial cell death and thus also the secondary injury cascade. The intermediate (14 days - 6 months after injury) and chronic (> 6 months after injury) phases are characterized by remyelination, vascular and neuronal reorganization and changes in the composition of the extracellular matrix.

[0009] The massive cell death and degeneration in the acute phase of spinal cord injury leads to the formation of a cystic cavity due to the loss of tissue volume. This cavity is particularly pronounced in humans and contains extracellular fluid, thin bands of connective tissue and macrophages. This cavity becomes denser as it progresses and forms a strong barrier against directed axonal growth. The formation of the cavity results in a disease process that can be divided into 3 spatial sections:

[0010] 1 . A perilesional zone comprising reactive astrocytes and inflammatory cells develops in front of the cavity. In the acute phase of spinal cord injury, the activity of these cells leads to the secretion of extracellular proteins, which impede axonal growth by condensing with astrocytes to form a glial scar. This inhibits axonal regeneration proximal to the scar as well as the sprouting of new neurites.

[0011] 2. Within the cavity, the migration and proliferation of fibroblasts, pericytes and oligodendrocyte progenitor cells leads to remodeling of the extracellular matrix of the glial scar. Together, these changes form a physical and biochemical barrier against regeneration. Over time, an imbalance develops at the molecular, cellular and tissue level compared to the healthy microenvironment of the spinal cord.

[0012] 3. Behind the cavity there is also an imbalance of neurotrophic factors as well as cytokines and chemokines due to hemorrhage, oedema and ischemia, activation of microglia and macrophages. This accelerates the demyelination of axons caudal to the lesion site and results in impaired differentiation of endogenous neural stem cells (NSCs).

[0013] This means that in spinal cord lesions, different processes occur simultaneously in at least 3 different places. Furthermore, these processes do not occur uniformly over time. While inflammation is in the foreground in the acute phase, reduced neurogenic growth is impaired in later phases.

[0014] In the acute treatment of spinal cord injuries, apart from surgical decompression of the myelon, there are hardly any clinically applied acute measures that improve the prognosis of healing and sufficiently promote the regeneration of the spinal cord after spinal cord injury.

[0015] In recent years, research into neuroregenerative capacities of growth factors such as neurotrophic growth factors (neurotrophics) - signalling proteins that promote neuronal growth - and immunomodulators has been intensified. These are messenger substances that provide signals to cells to grow and form tissue and specifically curb the excessive immune response and subsequent scarring in damaged tissue of a subject such as in spinal cord injury. Various research approaches have already attempted to use growth factors such as neurotrophics in spinal cord injuries to promote regeneration. Thereby, numerous factors, such as fibroblast growth factor, granulocyte colony-stimulating factor, hepatocyte growth factor and interleukin 4, have shown a positive effect on the regeneration of spinal cord injuries in animal models (Hodgetts et al., 2017). Several of these factors are now investigated in clinical trials (Ahuja et al., 2017). However, so far, these clinical studies have not been able to replicate the promoting effect of the factors / immunomodulators on regeneration observed in animal models to the same extent in humans.

[0016] The lack of effectivity of the factors / immunomodulators in clinical studies in humans can most likely be attributed to the following reasons:

[0017] 1) As stated above the pathophysiology of spinal cord injury is highly complex and influenced by several different processes that take place at different sites of the injury. The injection of a single therapeutic agent such as a therapeutic agent targeting inflammation (e.g., Elanuzumab, cortisone and IL-4), stimulating neuronal growth (e.g., hepatocyte growth factor, fibroblast growth factor, neurothrophi-3, BDNF-1 and GDNF-3) or reducing nerve degeneration (e.g., ALMB-0166, PMZ-1602 and MT-3921) is therefore not sufficient to address all pathological processes simultaneously (Alizadeh et al., 2019).

[0018] 2) The spinal cord is surrounded by fluid in a tube-like tissue, the dural sac, wherein a continuous flow of fluid takes place. A single injection of a therapeutic agent during surgical treatment is therefore unable to build up a sufficient level of active substances at the site of the injury, as the cerebrospinal fluid transports each substance away quickly (Silva et al. , 2021).

[0019] 3) The underlying pathological mechanisms take place both within and behind the area of injury (sometimes at a distance of several centimetres) and differ from each other (Ahuja et al., 2017). A single injection of a therapeutic agent to the site of injury is thus not sufficient to target also the pathological mechanisms occurring in close proximity to the injury.

[0020] In summary, the direct application of one or more therapeutic agents such as growth factors by injection or as liquid hydrogels such as monophasic, liquid hydrogels has not been successful to date, as the therapeutic agents do not arrive at the right place in the injury at the right time. The therapeutic agents are released undirected over the entire course of the injection or hydrogel injection. These undirected approaches are unable to exert the required, locally targeted pro- regenerative influence on the molecular microenvironment at the individual sites of injury.

[0021] CN101209240A discloses a cylindrical, polymer-based implant for controlled release of a drug substance (e.g. an anti-rheumatic, immunomodulatory, or analgesic drug substance). The implant comprises a bottom and upper layer, which prevent release of the drug substance. Between these two layers, there is an intermediate layer comprising a polymer and a drug substance. However, CN101209240A neither discloses the use of two drug substances within the implant, nor a blocking layer between drug substance-containing segments, which is impermeable for the drug substance(s), and which would thus separate areas within the implant. Use of the implant in the treatment of a spinal cord injury is also not disclosed in CN101209240A.

[0022] Despite the provision of means for the treatment of spinal cord injury in the prior art, these approaches do not take into account the complexity of spatially and temporally occurring processes involved in the underlying pathophysiology. There is thus the urgent need for developing therapeutics that address the different temporal and spatial aspects of medical conditions associated with damaged tissue and a complex pathophysiology such as spinal cord injury, in order to provide an effective treatment and promote long-term tissue regeneration.

[0023] SUMMARY OF THE INVENTION

[0024] In light of the prior art, the technical problem underlying the invention was the provision of alternative or improved means for the treatment of medical conditions associated with damaged tissue and / or a healing disorder such as spinal cord injury. One object of the invention was to provide improved or alternative means for compositions that allow the simultaneous application of two or more therapeutic agents to a damaged tissue of a subject such as tissue damaged upon spinal cord injury.

[0025] Another object of the invention was to provide improved or alternative means for compositions that are configured for timely and spatially controlled delivery and release of therapeutic agents to the tissue and thus provide an effective treatment of conditions associated with a complex temporally and spatially separated pathophysiology such as spinal cord injury.

[0026] Another object of the invention was the provision of improved or alternative means for compositions that are biodegradable and thus do not have to be removed after application to a damaged tissue of a subject.

[0027] Another object of the invention was the provision of a composition that can be produced in a versatile, simple and cost-effective manner.

[0028] These problems are solved by the features of the independent claims. Preferred embodiments of the present invention are provided by the dependent claims.

[0029] In one aspect, the invention relates to a composition configured for time and spatially controlled delivery of two or more therapeutic agents to a damaged tissue of a subject, characterized in that the composition is in a solid and planar form and comprises a basal layer, two or more segments attached to the basal layer and two or more therapeutic agents, wherein the two or more segments are horizontally arranged on the basal layer and are separated by a blocking layer, wherein the two or more segments comprise one or more polymer layers, wherein a first polymer layer is attached to the basal layer and one or more further polymer layers are vertically stacked on to the first polymer layer, and each of the two or more segments comprises one or more of the therapeutic agents in at least one polymer layer.

[0030] By the compositions of the present invention surprisingly two or more therapeutic agents can be simultaneously applied to a damaged tissue of a subject such as in the spinal cord in a single composition. Thereby, the compositions of the present invention advantageously allow the release of the two or more therapeutic agents at precisely defined time points, over defined timespans and at precisely defined locations of the damaged tissue and its immediate surroundings. The compositions of the present invention thus advantageously allow to address the individual pathophysiological processes occurring within or in spatial proximity of the damaged tissue with therapeutic agents required for the respective region of the tissue and at the respective time point without the need for multiple or staggered applications of different therapeutic agents, e.g., by multiple injections or multiple surgeries. The compositions according to the present invention thus advantageously allow the comprehensive treatment of the distinct pathophysiological mechanisms occurring temporally and spatially separated upon tissue damage (e.g., in the acute, subacute, intermediate or chronic phase and within the perilesional zone, cavity and behind the cavity of spinal cord injury) and thus allow an effective treatment and promote long-term regeneration of the tissue they are applied to. In contrast by the approaches of the prior art such as the direct injection of a single therapeutic agent into the damaged tissue of a subject, the therapeutic agents applied are released undirected over the course of application. This undirected release does not result in a sufficient level of therapeutic agent over a longer time, the injected agents often do not arrive at the right place at the right time and usually multiple injections are required to apply different therapeutic agents or in order to achieve a sufficient level of a therapeutic agent over a longer period of time.

[0031] The timely and spatially controlled release of therapeutic agents from the compositions of the present invention is advantageously achieved by the compositions comprising two or more segments, which are brought in contact with different regions of the damaged tissue of a subject.

[0032] The spatial segmentation of the compositions into two or more segments advantageously and surprisingly allows to introduce two or more different therapeutic agents within the compositions and to release these therapeutic agents independently of each other in a controlled manner at the specific sites of the tissue with which the respective segment of the compositions is in contact. For example, anti-inflammatory active ingredients and growth-promoting active ingredients can be released from the compositions at different times and to different regions of the damages tissue.

[0033] For instance, steroids can be released during the acute phase for decongestion, while pro- angiogenic, pro-regenerative, and / or neuroprotective factors can be released later, e.g. during the subacute phase.

[0034] Depending on the desired release kinetics of the respective therapeutic agent from a segment, the individual polymer layers of the respective segment may comprise different concentrations of therapeutic agent, different compositions of polymers and / or different polymer concentrations. If for example rapid release of a therapeutic agent from a segment of the composition according to the present invention is desired, the polymer layers of the segment close to the damaged tissue comprise the therapeutic agent, whereas more distant layers of the segment do not comprise the therapeutic agent. Further, for rapid release a therapeutic agent from a segment of the composition the concentration of polymers within the polymer layers of the segment close to the damaged tissue may be low and / or may comprise non-crosslinked polymers, resulting in fast dissolution of these polymers layers when contacted with the damaged tissue and rapid diffusion of the therapeutic agent from these polymers layers into the damaged tissue.

[0035] In case delayed release of a therapeutic agent from a segment of the composition according to the present invention is desired, the polymer layers of the segment in contact with or in close proximity to the damaged tissue, which dissolve first, may comprise no therapeutic agent, whereas the polymer layers of the segment more distant from the damaged tissue (closer to the basal layer) dissolving at a later timepoint comprise the therapeutic agent. Further, for delayed release the polymer layers of a segment may comprise a high concentration of polymers and / or polymer with a high degree of cross-linking resulting in slower dissolution of the polymer layers and slower diffusion of the therapeutic agent from the segment into the respective region of the tissue compared to polymer layers with lower polymer concentration and / or comprising noncrosslinked polymers or polymers with a lower degree of crosslinking. The chemical composition of the polymer layers with regards to polymer composition, crosslinking degree of the polymer, concentration and concentration of the therapeutic agent and their arrangement within a segment thus advantageously allows to precisely control the release of a therapeutic agent from the respective segment in a versatile manner.

[0036] In one embodiment the composition is in a solid form.

[0037] In one embodiment a segment may comprise two or more therapeutic agents. In one embodiment a polymers layer of a segment may comprise two or more therapeutic agents.

[0038] The basal layer surprisingly allows the provision of a flat, stable composition, which can also be applied to regions and tissues with very limited space, such as the spinal cord. In embodiments the composition of the present invention may be applied between the spinal cord and the dura mater (subdural application). For example, in embodiments the composition can be easily applied directly to the injured spinal cord during surgery and remain there after surgery for release of the therapeutic agents over a longer time. The basal layer provides sufficient stability for a simple and rapid application of the composition to the damaged tissue of a subject and thus advantageously enables the horizontal arrangement of various segments in a very flat form allowing application to spatially limited regions of the body of a subject such as the spinal cord and by subdural application.

[0039] The compositions of the present invention thus surprisingly provide a versatile platform for the temporally controlled and spatially separated application of several therapeutic agents in a single composition that can be easily adapted with regards to the therapeutic agents applied, their desired release kinetics and the spatial arrangement of the segments releasing the therapeutic agents as required for the respective medical application such as for subdural application to the spinal cord.

[0040] In one embodiment the basal layer, the blocking layer and the one or more polymer layers comprise one or more biodegradable polymers.

[0041] Advantageously, the polymer layers of the segments of the compositions according to the present invention dissolve and / or degrade due to comprising biodegradable polymers, which degrade when in contact with biological tissue such as a damaged tissue of a subject for example by enzymatic cleavage and / or hydrolysis. Due to the dissolution and degradation of the biodegradable polymers within the polymer layers the therapeutic agents are released form the respective segment into the damaged tissue of a subject in a controlled manner. Furthermore, the compositions of the present invention dissolve and / or degrade as a whole after a certain time in contact with biological tissue such as the tissue and thus do not have to be removed from the body of a subject after a certain time, for example by a further surgery or during an additional medical visit. Thus, no or only negligible amount and residues of the composition of the present invention remain in the damaged tissue subsequent to the application of the composition.

[0042] Furthermore, the polymers used advantageously show high biocompatibility and thus do not trigger any undesirable reactions when brought into contact with the tissue or when dissolved after a certain time. The polymers used also exhibit low reactivity, particularly with the majority of therapeutic agents. Thus, advantageously several different therapeutic agents can be incorporated into the composition of the present invention without showing any or only negligible interactions or reactions with the polymers comprised in the polymer layers of the segments. Furthermore, it is advantageously possible to incorporate therapeutic agents which, when in direct contact with each other interact and thus usually cannot be combined one pharmaceutical composition, into different segments of the composition of the present invention or even in one segment into different polymer layers. By the composition of the present invention, such chemically interacting active ingredients can thus advantageously also be formulated and applied in one single composition.

[0043] In one embodiment the basal layer and the blocking layer are impermeable for the two or more therapeutic agents.

[0044] As shown in the examples below the basal layer and the blocking layer are impermeable to the therapeutic agents comprised within the segments and thus advantageously impede and reduce undirected and lateral diffusion of the therapeutic agents from or within the composition, e.g., in direction of the basal layer, which is not in contact with the damaged tissue or within the different segments (see Fig. 5 to 11). The basal layer and blocking layer thus advantageously spatially directs the release from the segments of the composition to the damaged tissue in contact with the respective segment of the composition. The impedance of uncontrolled lateral diffusion within the composition further allows to precisely control the timely release of a therapeutic agent within a segment of the composition.

[0045] In one embodiment, the therapeutic agents are released in a unidirectional manner.

[0046] In one embodiment, the therapeutic agents are released in a unidirectional manner into the spinal cord.

[0047] In one embodiment the composition is prepared by a 3D-printing process comprising 3D-printing of the basal layer, the blocking layer and the two or more segments.

[0048] In one embodiment the basal layer is prepared by a 3D-prining process, preferably an electrospinning process. In one embodiment the basal layer is prepared by an electrospinning process. In one embodiment the basal layer is prepared by an electrospinning process of polylactic acid (PLA) and / or polycaprolactone (PCL). IN one embodiment the basal layer comprises PLA and / or PCL.

[0049] In one embodiment the blocking layer is prepared by a 3D-printing process, preferably an electrospinning process.

[0050] In one embodiment the composition is prepared by a 3D-printing process, preferably by a extrusion-based process.

[0051] In one embodiment the composition is prepared by a 3D-printing process, preferably fused filament fabrication (FFF) process.

[0052] The compositions of the present invention are preferably prepared by using a 3D printing process. Production by means of 3D printing technology enables particularly precise preparation of the composition and thus also a particularly precise control of the release of the therapeutic agents from the segments of the composition. By producing the composition layer by layer by a 3D-printing process, the composition of each layer can be customized, for example with regard to the concentration of the therapeutic agent, the polymer composition and concentration and the degree of crosslinking of the polymers. In one embodiment the 3D-printing process of a segment comprises printing a polymer layer and curing of the polymer layer by UV irradiation and / or the addition of ions to the polymer layer.

[0053] In particular, extrusion-based 3D printing technology allows to design compositions with complex microarchitecture, such as the compositions of the present invention, with resolutions of up to 50pm in Computer Automated Design (CAD) programs and then prepare them with high precision. This technology further allows to layer several polymer layers on top of each other and to prevent immediate mixing of the layers and the active ingredients comprised therein by selective curing of the layers, for example by UV irradiation or the addition of ions. This allows to arrange polymer layers containing different polymer concentrations and compositions and active ingredient concentrations in a highly selective manner and thus achieve a spatially and temporally controlled release of therapeutic agents from the layers and segments. Besides precisely arranging the different polymer layers within the segments of the compositions of the present invention it is possible to print ring-shaped diffusion barriers into the compositions and thus pre-define the diffusion direction of the therapeutic agents in the form of channels.

[0054] 3D printing technology thus allows the simple, particularly precise and versatile production of the compositions of the present invention. Compositions containing a wide variety of polymers and therapeutic agents, comprising the desired number of segments and enabling a precisely controlled release of the therapeutic agents due to the composition and arrangement of the polymer layers in these segments can be provided.

[0055] Furthermore, in particular the preparation of the compositions by an extrusion-based process such as the fused filament fabrication (FFF) process does not involve harsh conditions, such as high heat generation. The preparation of the compositions of the composition of the present invention thus does not affect the chemical properties and thus the efficacy of the therapeutic agents comprised in the compositions.

[0056] In one embodiment the one or more biodegradable polymers are selected from the group consisting of collagen or a derivative thereof such as gelatin, methacrylated collagen (ColMA) or methacrylated gelatin(GelMA), polyethylene glycol diacrylate(PEGDA), alginate or a derivative thereof such as methacrylated alginate, polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic-co-glycolic acid)(PLGA), methacrylated hyaluronic acid, chitosan and cellulose derivatives such as carboxymethylcellulose and agarose.

[0057] In one embodiment the one or more biodegradable polymers are selected from the group consisting of collagen, gelatin, methacrylated collagen (ColMA), methacrylated gelatin(GelMA), polyethylene glycol diacrylate(PEGDA), alginate, methacrylated alginate, polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic-co-glycolic acid)(PLGA), methacrylated hyaluronic acid, chitosan and carboxymethylcellulose and agarose.

[0058] In one embodiment the one or more biodegradable polymers are selected from the group consisting of alginate, methacrylate alginate, collagen, polylactic acid (PLA), gelatin, chitosan, polyethylene glycol diacrylate (PEGDA), methacrylated gelatin (GelMA), methacrylated collagen (ColMA), polycaprolactone (PCL) and poly(lactic-co-glycolic acid)(PLGA).

[0059] In one embodiment the one or more biodegradable polymers are selected from the group consisting of alginate, methacrylate alginate, collagen, polylactic acid (PLA), gelatin, chitosan, polyethylene glycol diacrylate (PEGDA), methacrylated gelatin (GelMA), methacrylated collagen (ColMA), polycaprolactone (PCL) and poly(lactic-co-glycolic acid)(PLGA).

[0060] Surprisingly, these polymers enable particularly good control of the release of the therapeutic agents from the composition and further show particularly good biocompatibility. Furthermore, these polymers are very easy to use in 3D printing processes and can therefore be used particularly well for the production of the composition according to the present invention by means of 3D printing.

[0061] In one embodiment the two or more segments comprise 1 to 20 polymer layers, preferably 2 to 15, more preferably 5 to 10. In one embodiment the two or more segments comprise 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, or 20 polymer layers.

[0062] In one embodiment one or more of the segments comprises at least two polymer layers, wherein a. the two or more polymer layers each comprise one or more of the therapeutic agents and wherein the concentration of the one or more therapeutic agents is increasing with each polymer layer stacked onto the first polymer layer, with the polymer layer most distant from the basal layer comprising the highest concentration of the one or more therapeutic agents, b. the two or more polymer layers alternately comprise one or more of the therapeutic agents or no therapeutic agent, or c. at least the first polymer layer comprises one or more of the therapeutic agents and at least the layer most distant from the basal layer comprises no therapeutic agent.

[0063] In one embodiment one or more of the segments comprises at least two polymer layers, wherein the concentration of the biodegradable polymer in the two or more polymer layers is increasing with each polymer layer stacked onto the first polymer layer, with the polymer layer most distant from the basal layer comprising the highest concentration of the biodegradable polymer.

[0064] In one embodiment the one or more polymer layers comprise one or more biodegradable polymers with a concentration of 1 to 20 wt% of the polymer layer, preferably 2 to 15 wt%, more preferably 4 to 10 wt%. In one embodiment the one or more polymer layers comprise one or more biodegradable polymers with a concentration of 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, or 20 wt% of the polymer layer.

[0065] In one embodiment the one or more polymer layers comprise a crosslinked biodegradable polymer with a degree of crosslinking of 50 to 100 %, preferably 65 to 90 %, more preferably 80 to 90 %. In one embodiment the one or more polymer layers comprise a crosslinked biodegradable polymer with a degree of crosslinking of 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100 %.

[0066] Advantageously, the degree of crosslinking of the polymers and the concentration of crosslinked polymer in a polymer layer can be used to easily and precisely control the dissolution and / or degradation of the layers and thus the diffusion of the therapeutic agent from the polymer layer. Polymers with a higher degree of crosslinking dissolve more slowly and thus delay the release of the therapeutic agents from a polymer layer and a segment compared to non-crosslinked polymers or polymers with a lower degree of crosslinking. In one embodiment the composition comprises three or more segments. In one embodiment the composition comprises three or more segments, such as 3, 4, 5, 6, 7, 8, 9 or 10 segments.

[0067] In one embodiment one or more of the segments additionally comprises a ring-shaped blocking layer, wherein the ring-shaped blocking layer is impermeable for the two or more therapeutic agents.

[0068] Surprisingly, the insertion of a ring-shaped blocking layer enables the even more specific spatial release of a therapeutic agent from a segment. The ring-shaped blocking layer is impermeable for a therapeutic agent and prevents the lateral diffusion of the therapeutic agent, which are introduced into the area inside the ring-shaped blocking layer. As a result, the direction of diffusion of the therapeutic agent in this particular area within the segment is predefined in the form of a channel. This allows to direct the release of the therapeutic agent outlet with precision of a few millimeters (mm), such as 5, 4, 3, 2, 1 or 0.5 mm.

[0069] In one embodiment one or more of the segments additionally comprise nanoparticles and / or microparticles, wherein the nanoparticles and / or microparticles comprise one or more therapeutic agents.

[0070] In one embodiment the two or more therapeutic agents are selected from the group consisting of a neurotrophic growth factor, an anti-inflammatory agent, an inhibitor of neurodegeneration and an inhibitor of glial scar formation.

[0071] In one embodiment the two or more therapeutic agents are selected from the group consisting of a neurotrophic growth factor, an anti-inflammatory agent, an inhibitor of neurodegeneration, an inhibitor of glial scar formation, a small molecule, a corticosteroid, such as methylprednisolone, and a pro-angiogenic agent, or a combination of two or more of the aforementioned therapeutic agents.

[0072] In specific embodiments, neurotrophic factors are replaced by corticosteroids, such as methylprednisolone.

[0073] In specific embodiments, a small molecule is used as the therapeutic agent for spinal cord injury, preferably Riluzol (6-(Trifluormethoxy)-1 ,3-benzothiazol-2-amin).

[0074] In one embodiment a. the one or more polymer layers each have a thickness of 50 to 300 pm, preferably 75 to 200 pm, more preferably 100 to 150 pm, b. the blocking layer has a thickness of 100 to 500 pm, preferably 150 to 400 pm, more preferably 200 to 300 pm, and / or c. the basal layer has a thickness of 100 to 600 pm, preferably 200 to 500 pm, more preferably 300 to 400 pm.

[0075] In one embodiment a. the one or more polymer layers each have a thickness of 50, 60, 70, 80, 90, 100, 1 10, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290 or 300 pm, b. the blocking layer has a thickness of 100, 110, 120, 130, 140, 150, 160, 170, 180, 190,

[0076] 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370,

[0077] 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490 or 500 pm, and / or c. the basal layer has a thickness of 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200,

[0078] 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380,

[0079] 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560,

[0080] 570, 580, 590 or 600 pm.

[0081] The compositions of the present invention can surprisingly be provided in a particularly flat form while maintaining high stability and precise control of timely and spatial release of the two or more therapeutic agents. The composition of the present invention can thus also applied to regions such as the spinal cord, such as by subdural application, which at the same time possess a highly complex pathophysiology requiring a highly controlled timely and spatially release of different therapeutic agents.

[0082] In one embodiment the blocking polymer layer and / or the basal layer comprise polylactic acid (PLA), polycaprolactone (PCL), polylactid-co-glycolide (PLGA) and / or a mixture thereof.

[0083] In a further aspect the invention relates to the composition according to the present invention for use in the treatment of a medical condition associated with a healing disorder.

[0084] In one embodiment the medical condition associated with a healing disorder is selected from the group consisting of a central nervous system (CNS) disease, traumatic brain injury, spinal cord lesion, a peripheral nerve injury, ischemic nerve injury, stroke, and a healing disorder associated with a metabolic disorder.

[0085] In one embodiment the medical condition associated with a healing disorder is a spinal cord injury.

[0086] The features of the invention relating to the composition as described herein, are relevant to and considered disclosed in combination with other aspects of the invention, such as the use of the composition in the treatment of a medical condition associated with a healing disorder and vice versa. For example, the composition and use are immediately relevant to the other aspects of the invention and may be used to characterize them appropriately, as understood by a skilled person.

[0087] DETAILED DESCRIPTION OF THE INVENTION

[0088] The term “controlled delivery” or “controlled release” refers to release of a therapeutic agent from a composition, such as a pharmaceutical composition at a specified place, over a specified period of time and / or at a specified timepoint to the tissue the pharmaceutical composition is applied to. The term “timely controlled release” or “timely controlled delivery” in the context of the present invention refers to the release of a therapeutic agent from the composition of the present invention such as by diffusion at a specified time point after application of the composition to a damaged tissue of a subject and / or the continuous release of a therapeutic agent over a specified timespan such as over 1 , 6, 12, 24, 26, 48, 60 or 72 h , 1 , 2, 3, 4, 5, 6, 7 days, or up to multiple weeks such as 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 15 and 20 weeks after application of the composition to a damaged tissue of a subject. The term “spatially controlled release” or “spatially controlled delivery” refers to release of a therapeutic agent from the composition according to the present invention at a specific place of the tissue. “Spatially controlled release” from the composition of the present invention refers to release from a segment of the composition to the tissue the segment is in contact with. “Spatially controlled release” may further refer to release of a therapeutic agent from specific parts of the segment to the tissue these parts of the segment are in contact with, such as release from the areas within a ring-shaped blocking layer within the segment or from a nanoparticle or microparticle embedded in the segment.

[0089] The term “implant” or “composition” in the context of the present invention refers to a solid pharmaceutical composition in a planar form that is applied to damaged tissue of a subject such as in the spinal cord during surgery. “Application” in the context of the present invention refers to placing the composition on the damaged tissue such as on the spinal cord during surgery. In embodiments the composition according to the present invention is not removed after application to the tissue such as by a subsequent surgery. In embodiments the pharmaceutical composition according to the present invention is biodegradable. “Biodegradable” in the context of the present invention refers to the composition dissolving and / or degrading after application to biological tissue such as damaged tissue of a subject such as by hydrolysis or enzymatic degradation resulting in the formation of biocompatible, non-toxic molecules that can either be metabolized or eliminated via the body's natural excretory pathways.

[0090] The term “planar” refers to an object such as the solid composition according to the present invention, which is characterized by a low height and a flat surface. The surface, i.e. the width and / or depth of the object are usually greater than the height of the object.

[0091] The term “horizontally arranged on the basal layer” refers to the segments of the composition of the present invention being placed next to each other on the basal layer. An example for such horizontal arrangement of the segments is disclosed in Figure 1.

[0092] The term “vertically stacked” or “vertically stacked on the first polymer layer” refers to the polymer layers of a segment of the composition of the present invention being stacked on top each other, wherein the first polymer layer of a segment is attached to the basal layer and the second polymer layer is attaches (“stacked”) to the first polymer layer, a third polymer layer is attached (“stacked”) to the second polymer layer, a fourth polymer layer is attached (“stacked”) to the third polymer layer, and so on.

[0093] The term “impermeable” or “impermeable for the two or more therapeutic agents” refers to a material or part of the composition according to the present invention such as the basal layer or blocking layer, characterized in that no or only negligible amount of a therapeutic agent diffuse into or through this material or part of the composition of the present invention. A person skilled in the art is aware of methods to determine whether a material or part of a composition is impermeable for a therapeutic agent. Such methods include for example the Diffusion Cell Method (Permeation Cell Method), wherein two chambers are separated by the material or part under investigation and one chamber contains the therapeutic agent to be diffused through the material, while the other chamber is initially empty or contains a solvent. The concentration of the substance in the second chamber is measured overtime to determine the diffusion rate and, consequently, the permeability of the material or part of the composition. The term “blocking layer” refers to a layer that is placed in between the horizontally arranged segments of the composition of the present invention, wherein the blocking layer is preferably impermeable for the two or more therapeutic agents comprised in the composition according to the present invention. Placing a blocking layer in between the two or more segments thus advantageously results in spatial control of the release of the therapeutic agents from the segments of the composition.

[0094] The term “basal layer” refers to a layer of the composition according to the present invention on to which the segments and the blocking layer are attached. In embodiments the basal layer is preferably impermeably to the one or more therapeutic agents comprised in the segments of the composition according to the present invention. The basal layer advantageously serves as support for the segments of the present invention and further, results in spatial control of the release of the therapeutic agents from the segments of the composition.

[0095] The term “nanoparticle” refers to a particle sized in the nanometer range (1 to 1000 nm). A nanoparticle typically has dimensions of less than 100 nanometers in at least one dimension, such as in diameter. Nanoparticles according to the present invention can comprise various materials, including without limitation polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic- co-glycolic acid)(PLGA) polyethylenimine (PEI), polyethylene glycol (PEG), silicon dioxide, phospholipids, triglycerides, albumin, gelatin, chitosan, alginate, dextran and / or cellulose.

[0096] The term “microparticle” refers to particles sized in the micrometer range (1 to 1000 pm).

[0097] Mirkoparticles according to the present invention can comprise various materials, including without limitation polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic-co-glycolic acid)(PLGA), Polyethylene glycol (PEG), alginate, chitosan, dextran, cellulose, silicon dioxide, triglycerides and / or albumin.

[0098] In one embodiment, the microparticles are degraded in a targeted manner and / or residue-free.

[0099] In one embodiment, microparticles are formed using spray drying.

[0100] “Spray drying” as used herein refers to a method of forming a dry powder or microparticles from a liquid by rapidly drying with a hot gas. It preferably refers to a process, wherein liquid is atomized, thereby forming small droplets, which are dried in the air flow and subsequently separated from the drying air.

[0101] Advantageously, spray drying enables the production of very consistent, fine particle sizes and is particularly suitable forthermally-sensitive materials, such as some therapeutic agents. In embodiments, the gas is selected from the group consisting of compressed air, gas, such as nitrogen, and steam.

[0102] Hence, in embodiments, spray drying is used to encapsulate a substance, such as a therapeutic agent, into a carrier (e.g. polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic-co-glycolic acid)(PLGA), Polyethylene glycol (PEG), alginate, chitosan, dextran, cellulose, silicon dioxide, triglycerides and / or albumin). In one embodiment, the carrier and the substance are mixed into a liquid or slurry and put into a spray dryer, usually a tower heated to temperatures above 99.98°C. The mixture is atomized (e.g. by using a spray nozzle, such as a two-substance nozzle or three- substance nozzle) upon entry into the tower and micelles are formed, which dry quickly due to their small size and relatively large surface area. The carrier thus forms a macroparticle around the substance.

[0103] In one embodiment, microparticles are formed using a two-substance nozzle.

[0104] In one embodiment, i) a liquid to be atomized and ii) compressed air, or gas, such as nitrogen, or steam are used with a “two-substance nozzle” for atomization. In embodiments, the flow speed of the compressed air, or gas, such as nitrogen, or steam creates droplets of the liquid.

[0105] In an alternative embodiment, microparticles are formed using a three-substance nozzle.

[0106] In one embodiment, i) one or two liquids to be atomized and ii) compressed air, or gas, such as nitrogen, or steam are used with a “three-substance nozzle” for atomization.

[0107] Crosslinking of polymers refers to the formation of covalent bonds and / or non-covalent interactions such as electrostatic and / or hydrophobic interactions between polymer chains, resulting in a three-dimensional network structure. Crosslinking alters the physical and chemical properties of the polymer. Crosslinking can occur through various methods, including radiation, thermal treatment or the addition of ions, such as calcium ions resulting in crosslinking of alginate. The degree of crosslinking in the context of the present invention refers to the extent to which polymer chains are interconnected through crosslinking bonds and / or non-covalent interactions and quantifies the density or concentration of such bonds and interactions (crosslinks) within the polymer network. A higher degree of crosslinking indicates a greater number of crosslinks per unit volume or weight of the polymer. A person skilled in the art is aware of method for determining the degree of crosslinking. Such methods may include measurement of the degree of crosslinking by swelling tests. The crosslinked sample is placed into a good solvent at a specific temperature, and either the change in mass or the change in volume is measured. The higher the number of crosslinks, the less swelling is attainable. Based on the degree of swelling, the Flory Interaction Parameter (which relates the solvent interaction with the sample), and the density of the solvent, the theoretical degree of crosslinking can be calculated according to Flory's Network Theory.

[0108] The term “biodegradable polymer” refers to synthetic or natural polymers that undergo degradation through biological processes such as enzymatic activity or hydrolysis within a predefined timeframe after application to biological tissue such as damaged tissue of a subject. Degradation of said biodegradable polymer results in the formation of biocompatible, non-toxic small molecules that can either be metabolized or eliminated via the body's natural excretory pathways. These polymers usually have a high biocompatibility and no or only low long-term adverse effects on biological tissue or physiological functions of the body of a subject. Biodegradable polymers include without limitation gelatin, methacrylated collagen (ColMA), methacrylated gelatin(GelMA), polyethylene glycol diacrylate(PEGDA), alginate or a derivative thereof such as methacrylated alginate, polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic-co-glycolic acid)(PLGA), methacrylated hyaluronic acid, chitosan and cellulose derivatives such as carboxymethylcellulose and agarose.

[0109] "3D printing" refers to a process in which the compositions according to the invention are produced and prepared by applying individual layers of material. In particular, the materials are applied layer by layer such as a polymer layer is applied onto the basal layer or on to of another polymer layer. Exemplary 3D processes, without being limited thereto, are fused filament fabrication (FFF), stereolithography (SLA), selective laser sintering (SLS), digital light processing (DLP), binder jetting (BJ), material jetting (MJet), electron beam melting (EBM), electrospinning and laminated object manufacturing (LOM). Extrusion-based processes such as the fused filament fabrication (FFF) process are particularly preferred for the preparation of the compositions according to the present invention, in particular for preparation of the segments of the composition of the present invention.

[0110] Fused filament fabrication (FFF) is an additive manufacturing technique where a filament such as a filament comprising a polymer is extruded through a nozzle and deposited layer by layer onto a build platform. The nozzle moves according to the three-dimensional shape of the desired object, with each layer of extruded material being deposited onto the previous layer. This process creates the desired three-dimensional object such as the composition of the present invention in the form of a solid planar implant.

[0111] In a preferred embodiment, the 3D printing process does not comprise a thermal melting step of the polymer(s). Instead, in preferred embodiments, the 3D printing process is based on direct extrusion of the polymer(s) and the therapeutic agents as liquids or gels.

[0112] Electrospinning is a manufacturing process used to produce nanofibers by utilizing the principles of electrostatic forces. In this process, a high-voltage electric field is applied to solution or melt, usually a polymer solution or melt, which is held in a syringe or a similar reservoir with a smalldiameter nozzle. Apart from polymers, inorganic, metallic or ceramic materials are employed for electrospinning. The electric field induces a charge on the surface of the polymer solution or melt, creating a force that overcomes the surface tension and leads to the formation of a Taylor cone at the nozzle tip. From this cone, a fine jet of the polymer solution or melt is ejected and stretches as it travels through the electric field. The jet undergoes bending and whipping motions, further thinning into fibers with diameters in the nanometer range. These fibers are collected on a grounded or oppositely charged collector, forming a non-woven mat or fabric. Electrospun nanofibers are utilized in various applications including filtration, medical textiles, tissue engineering scaffolds, and composite materials. In embodiments one or more therapeutic agents are encapsulated in the material used for the electrospinning process. In embodiments a segment is prepared by an electrospinning process. In embodiments a segment is prepared by an electrospinning process, wherein one or more therapeutic agents are encapsulated in the material used for the electrospinning process. In one embodiment the one or more polymer layers of a segment are prepared by an electrospinning process. In one embodiment the one or more polymer layers of a segment are prepared by an electrospinning process, wherein one or more therapeutic agents are encapsulated in the material used for the electrospinning process. In embodiments the basal layer is prepared by an electrospinning process.

[0113] In embodiments, the one or more therapeutic agents are released from electrospun nanofibres.

[0114] In some embodiments, the one or more therapeutic agent is a small molecule. In some embodiments, the small molecule is released from electrospun nanofibers. A “small molecule” as used herein in relation to a therapeutic agent refers to an organic compound having a low molecular weight (usually < 1000 daltons) that can regulate a biological process and / or infer with a biological function or activity of a target molecule.

[0115] "Injured tissue” or “damaged tissue” refers to tissue and body parts of a subject that are damaged and limited in their normal function, for example caused by an external impact such as an injury or by a disease. Damaged tissue may for example include, without limitation peripheral nerves, central nerves, the spinal cord, muscles, ligaments, tendons, and the skin and underlying tissue.

[0116] The term “healing disorder”, “medical condition associated with a healing disorder” or “medical condition associated with impaired healing” refers to a medical state or condition wherein the physiological process of wound healing or tissue regeneration is disrupted or not functioning resulting in delay, slow down, or even no wound healing, leading to chronic wounds, impaired function of the tissue or other complications such as paralysis after spinal cord injury. Medical conditions associated with a healing disorder include without limitation metabolic disorders such as diabetes mellitus, vascular diseases such as peripheral arterial disease (PAD), chronic venous insufficiency, rheumatoid arthritis, immunosuppression due to conditions such as HIV / AIDS, chronic skin conditions such as psoriasis and eczema, genetic disorders such as Ehlers-Danlos syndrome and epidermolysis bullosa, cancer, intestinal disorders, diseases of the central nervous system (CNS), traumatic brain injury, spinal cord lesion and peripheral nerve injuries. These medical indications represent preferred embodiments of the medical use of the invention in the treatment of a medical condition associated with a healing disorder.

[0117] In one embodiment, wound healing following a gastrointestinal surgery is aided to avoid the resulting fibrosis.

[0118] A disease of the central nervous system (CNS) refers to any pathological condition that causes structural, biochemical, or electrical dysfunctions in the brain, spinal cord, or the neural connections between these two organs. This includes, but is not limited to, neurodegenerative diseases (such as Alzheimer's disease and Parkinson's disease and amyotrophic lateral sclerosis (ALS)), autoimmune diseases (such as Multiple Sclerosis), congenital malformations (such as spina bifida), traumatic injuries (such as spinal cord injuries), infectious diseases (such as meningitis), vascular disorders (such as stroke), and tumors of the CNS.

[0119] A “spinal cord injury” (SCI) refers to damage to the spinal cord that results in a loss of function, such as mobility or sensation, which may be caused by a trauma, such as an accident, fall, blow, or cut. Spinal cord injuries can lead to varying symptoms depending on the location and severity of the injury, including but not limited to partial or complete loss of motor control (paralysis), loss or impairment of sensation, including the ability to feel heat, cold, and touch, bladder and bowel dysfunction, altered reflex functions or spasticity, pain or intense tingling due to nerve damage in the affected area.

[0120] "Traumatic Brain Injury” (TBI) refers to any structural damage or functional impairment of the brain caused by an external mechanical force, leading to a disruption of normal brain function. This definition includes, but is not limited to, injuries resulting in a change in the state of consciousness, memory loss, language disorders, motor coordination disturbances, or alterations in emotional or behavioral functioning. The classification of TBI can be based on the severity of the injury as mild, moderate, or severe, measured by parameters such as loss of consciousness, memory loss, and neurological findings."

[0121] A “peripheral nerve injury” refers to any type of damage or disorder affecting the peripheral nerves, which are located outside the central nervous system (brain and spinal cord). Peripheral nerve injuries may be associated with a variety of causes, including without limitation physical trauma (e.g., cuts, crushes, or stretches), infections, systemic diseases (such as diabetes), toxins, medications, and genetic predispositions. The symptoms and severity of the injury may vary, depending on the nerves being affected and the extent of the damage. Possible symptoms include weakness, numbness, tingling, pain, and / or loss of function in the affected areas.

[0122] "Ischemic nerve injury" refers to a type of nerve damage caused by inadequate blood supply to the nerve tissue. Ischemia occurs when the blood supply to a tissue, in this case a nerve, is reduced or interrupted, leading to a lack of oxygen and nutrients. Ischemic nerve injury may have various causes, including without limitation traumatic injuries, compression, or blockage of blood vessels. Ischemic nerve injuries can result in numbness, weakness, pain, and other neurological symptoms, depending on the severity of the damage and the nerves affected.

[0123] "Administration" or "treatment," as it applies to an animal, human, experimental subject, cell, tissue, organ, or biological fluid, refers to contact of a pharmaceutical, therapeutic, diagnostic agent, compound, or composition to the animal, human, subject, cell, tissue, organ, or biological fluid. "Administration" and "treatment" can refer, e.g., to therapeutic, placebo, pharmacokinetic, diagnostic, research, and experimental methods. Administration in the context of the present invention preferably refers to placing the composition of the present invention to the damaged tissue of a subject.

[0124] The term "subject" includes both human and veterinary subjects. "Treatment," as it applies to a human, veterinary, or research subject, refers to therapeutic treatment, prophylactic or preventative measures, to research and diagnostic applications.

[0125] The invention encompasses administration of an effective amount of therapeutic agents as described herein to a subject or patient in need thereof. "Effective amount" or "therapeutically effective amount" means an amount sufficient to elicit an appreciable biological response such as ameliorate a symptom or sign of a disorder or physiological condition when administered to a subject or patient. An effective amount for a particular patient or veterinary subject may vary depending on factors such as the condition being treated and the overall health and age of the patient. An effective amount can be the maximal dose or dosing protocol that avoids significant side effects or toxic effects.

[0126] The term “therapeutic agent”, "active ingredient" or “API” herein refers to a pharmaceutically active molecule as well as a pro-drug transformed to the pharmaceutically active molecule in the organism, and a pharmaceutically acceptable and / or therapeutically active salt thereof. The term further refers to pharmaceutically acceptable and therapeutically active hydrates, esters, amides, metabolites, enantiomers, polymorphs, analogs, etc. that induce a desired pharmacological or physiological effect or induce a desired pharmacological or physiological effect upon transformation to a pharmaceutically active molecule in the organism. Terms like “therapeutic agent”, "active agent", "active pharmaceutical ingredient", “drug substance”, may be used synonymously for "active ingredient".

[0127] The compositions are described herein in some embodiments according to “wt%”, or “percentage by weight” or “% by weight. The %wt values recited herein preferably relate to the percentage of material by weight present in the composition in the form of a solid and planar implant or in a part of the composition such as a segment or a polymer layer.

[0128] The term “anti-inflammatory agent” also termed “antiphlogistic agent” refers to a therapeutic agent that alleviates or suppresses inflammation. Inflammation is the local and systemic reaction of a biological system to an internal or external stimulus such as pathogens, damaged cells, toxins, or irritants. It is characterized by the activation of the immune system, aiming to eliminate the initial cause of cell injury, clear out necrotic tissue, and initiate tissue repair. The process of inflammation is mediated by a series of biochemical and cellular events, including the release of mediators like histamine, prostaglandins, and cytokines, which lead to vasodilation, increased vascular permeability, recruitment of immune cells, and further inflammatory responses. Inflammatory reactions can be categorized into acute and chronic inflammation. Acute inflammation is an immediate and temporary response, marked by prominent signs such as redness, heat, swelling, pain, and loss of function. Chronic inflammation is a prolonged response, characterized by the continuous presence of the initiating stimulus and a progressive change in the involved cells and tissues, ultimately leading to tissue damage and disease. Anti-inflammatory agents include without limitation Nonsteroidal Anti-inflammatory Drugs (NSAIDs) such as ibuprofen, naproxen, and acetylsalicylic acid, glucocorticoids such as prednisolone, dexamethasone, and hydrocortisone, immunosuppressants such as cyclosporine, methotrexate, azathioprine, Janus Kinase Inhibitors (JAK) such as baricitinib and tofacitinib, interleukin inhibitors such as secukinumab and anakinra, and further therapeutic agents such as elanuzumab and interleukin-4 (IL-4).

[0129] The term “neurotrophic growth factors” refers to proteins that support the survival, growth, and differentiation of neurons in the nervous system. Neurotrophic growth factors play a critical role in the development of the nervous system, repair after injury, and maintenance of neuronal functions in the adult brain. These factors bind to specific receptors on the surface of neurons, activating signaling pathways that promote cell growth and ensure cell survival. Neurotrophic factors include without limitation Nerve Growth Factor (NGF), proNGF, Brain-Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT-3), Neurotrophin-4 / 5 (NT-4 / 5), Ciliary Neurotrophic Factor (CNTF), Fibroblast Growth Factor (FGF), Artemin (ARTN), Glial Derived Neurotrophic Factor (GDNF), Glial Derived Neurotrophic Factor s (GDNF-3), Neurturin (NRTN), Persephin (PSPN), Neuregulin-1 , Neuregulin-2, Neuregulin-3 and Neuregulin-4.

[0130] “Inhibitor of neurodegeneration” refers to a compound that slows down, prevent, and / or reverses the process of neurodegeneration. Neurodegeneration refers to the progressive loss of structure or function of neurons, including their death. Inhibitors of neurodegeneration can act through various mechanisms, including without limitation antioxidant mechanisms, anti-inflammatory mechanisms, modulation of neurotransmitter levels, enhancement of neuronal survival and function and reduction of protein aggregation. Inhibitor of neurodegeneration include without limitation ALMB-0166, PMZ-1620 (solvatelide), MT-3921 (unasemab), memantine, riluzole, donezipil, rivastigmine, galantamine, natalizumab and teriflunomide.

[0131] The term “inhibitor of glial scar formation” refers to a compound that inhibits or reduces the formation of glial scars in the brain or the spinal cord such as after spinal cord injury. Glial cells are a type of cells in the central nervous system that perform various functions, including supporting and insulating neurons. Under certain conditions, such as after injury or in neurodegenerative diseases, glial cells can react excessively and form a type of scar tissue known as glial scar. This scar tissue can impair the regeneration and function of neural tissue. Inhibitors of glial scar formation include without limitation chondroitinase ABC, anti-inflammatory agents such as NSAIDs, decorin, peptide inhibitors such as P12 and inhibitors of transforming growth factor-beta (TGF-p) pathway such as SB-431542.

[0132] FIGURES

[0133] The invention is demonstrated by way of the figures disclosed herein. The figures provide support for a detailed description of potentially preferred, non-limiting embodiments of the invention.

[0134] Brief description of the figures

[0135] Fig. 1 : Schematic representation of an exemplary composition according to the present invention in a solid form, comprising a basal layer and three segments attached to the basal layer, which are separated from each other by a blocking layer.

[0136] Fig. 2 : Cumulative release of hemoglobin from a segment comprising different concentrations of alginate (t = 0 to 24 h).

[0137] Fig. 3 : Cumulative release of hemoglobin from a segment comprising different concentrations of alginate in the initial release phase (t = 0 to 180 min).

[0138] Fig. 4: Polylactic acid (PLA) as basal layer of the composition.

[0139] Fig. 5: Polylactic acid (PLA) as basal layer of the composition with an additional wall border (barrier) for impeding lateral diffusion.

[0140] Fig. 6: Polylactic acid (PLA) basal layer reduces release rate of hemoglobin from alginate segment.

[0141] Fig. 7 : Influence of alginate concentration on hemoglobin release rate from a composition comprising a Polylactic acid (PLA) basal layer and an alginate segment.

[0142] Fig. 8 : Variations of the height of the additional wall border (barrier) for impeding lateral diffusion of a polylactic acid (PLA) basal layer (wall thickness: 1 mm, wall height 0.3 mm).

[0143] Fig. 9 : Variations of the height of the additional wall border (barrier) for impeding lateral diffusion of a polylactic acid (PLA) basal layer (wall thickness: 0.46 mm, wall height 0.3 mm).

[0144] Fig. 10: Variations of the height of the additional wall border (barrier) for impeding lateral diffusion of a polylactic acid (PLA) basal layer (wall thickness: 0.46 mm, wall height 0.07 mm). Fig.11 : Influence of wall height of the PLA basal layer on hemoglobin release rate from an alginate segment.

[0145] Fig.12: Schematic overview on experimental implementation of in vivo release of lysozyme from the composition in comparison to direct injection of lysozyme into the spinal cord.

[0146] Fig.13: Weight and basso mouse scale in mice after sham-surgery (placebo; Sham SCI) and after the composition is implanted to the spinal cord (Sham SCI_TE).

[0147] Fig.14: Catwalk gait analysis 7 days after implantation of the composition (Sham SCI Patch) or Sham-surgery (placebo, Sham SCI).

[0148] Fig.15: Determination of the lysozyme content in the spinal cord post-implantation by an ELISA.

[0149] Fig. 16: Quantitative evaluation of the MRI analysis after the composition is implanted to the spinal cord.

[0150] Fig. 17: Quantitative evaluation of the immunohistochemistry (IHC)-analysis after the composition is implanted to the spinal cord.

[0151] Fig. 18: Lysozyme release from microparticles into an aqueous solution.

[0152] Fig. 19: Lysozyme release from microparticles embedded in a hydrogel into the hydrogel.

[0153] Detailed description of the figures

[0154] Fig. 1 : Schematic representation of an exemplary composition according to the present invention in a solid form comprising a basal layer and three segments attached to the basal layer, which are separated from each other by a blocking layer. (A) Segment comprising a therapeutic agent without biomaterial stratification. In the different layers, different concentrations of the therapeutic agent are imprinted in the same biomaterial composition (therapeutic agent is represented by grey spheres). The release begins immediately and first proceeds in an approximately linear increasing and then decreasing curve. (B) Segment comprising a therapeutic agent with an upstream stratified polymer layer. Polymer layers with varying degrees of cross-linking are lined up close to the tissue in decreasing concentrations (symbolized by different shades of grey, with light grey representing lower degree of cross-linking and dark grey representing higher degree of cross-linking). Due to the delay caused by degradation of the cross-linked polymers of the stratified polymer layer, release of the therapeutic agent begins after a certain time and increases exponentially. (C) Segment comprising a therapeutic agent. The segment comprises alternating layers comprising a high concentration of one or more polymers (diffusion-limiting layer) and layers comprising a therapeutic agent (therapeutic agent layer). Each therapeutic agent layer is preceded by a strongly diffusion-limiting layer. The degradation process of the next diffusionlimiting layer, which already begins during the release of the therapeutic agent from the therapeutic agent layer, generates a continuous release of the therapeutic agent over a longer period of time. (D) Diffusion-restrictive barrier layer (Blocking layer). A vertical layer of a highly cross-linked polymer, such as highly crosslinked alginate, that separates the segments of the from each other and prevents lateral transfer of the therapeutic agent into another segment. (E) Diffusion-restrictive anchor layer (basal layer). A layer to which the segments are laterally attached to ensure the mechanical-structural integrity of the composition in form of a solid and planar implant. The basal layer may additionally comprise an outer border or wall that impedes lateral diffusion of the therapeutic agent.

[0155] Fig. 2 : Cumulative release of hemoglobin from a segment comprising different concentrations of alginate (t = 0 to 24 h). The segments comprise either 4% (w / v), 6% (w / v) or 8% (w / v) alginate within the layers of the segment and in total 550 pg hemoglobin per segment. Within 1 h a primary release of hemoglobin is observed (initial release phase), whereas a plateau is reached after 6 h.

[0156] Fig. 3 : Cumulative release of hemoglobin from a segment comprising different concentrations of alginate in the initial release phase (t = 0 to 180 min). The segments comprised either 4% (w / v), 6% (w / v) or 8% (w / v) alginate within the layers of the segment and in total 550 pg hemoglobin per segment. Within the initial release phase, a slower release of hemoglobin is observed with increasing alginate concentration. After 180 min a similar amount of hemoglobin is released at all alginate concentrations tested. The cumulative release and release rate of hemoglobin is thus dependent on the alginate concentration within the layers of the segment.

[0157] Fig. 4: Polylactic acid (PLA) as basal layer of the composition. A basal layer (size 22 x 22 x 0,3 mm) was printed by a 3D-printing process (FDM technique). Within the basal layer periodic bumps were imprinted to increase the adhesion of the segments to the basal layer. (A) 3D- printing template of the basal layer, (B) to (D) light microscopic images of the basal layer from different angles (scale bar 5 mm).

[0158] Fig. 5: Polylactic acid (PLA) as basal layer of the composition with an additional wall border (barrier) for impeding lateral diffusion. A basal layer (size 22 x 22 x 0,3 mm) was printed by a 3D- printing process (FDM technique). Within the basal layer periodic bumps were imprinted to increase the adhesion of the segments to the basal layer. (A) 3D-printing template of the basal layer, (B) to (D) light microscopic images of the basal layer from different angles (0.8x magnification). Additionally, a border (1 mm thick) has been included in the basal layer to decrease and impede lateral diffusion from the composition.

[0159] Fig. 6: Polylactic acid (PLA) basal layer reduces release rate of hemoglobin from alginate segment (t = 0 to 60 min). PLA basal layer with and without an additional border for impeding lateral diffusion (PLA-sheet with wall and PLA -sheet) reduce release of hemoglobin in comparison to an alginate segment without a basal layer. PLA basal layer with the additional border impeding lateral diffusion (PLA-sheet with wall) reduces hemoglobin release by 50 % after 60 minutes in comparison to an alginate segment without a basal layer. The release rate from the segment can thus effectively be controlled by the basal layer.

[0160] Fig. 7 : Influence of alginate concentration on hemoglobin release rate from a composition comprising a Polylactic acid (PLA) basal layer and an alginate segment. The segments comprised either 4% (w / v), 6% (w / v) or 8% (w / v) alginate within the layers of the segment and in total 550 pg hemoglobin per segment. After 24 h the highest cumulative release was observed for the segment comprising 4% (w / v) alginate (500 pg released), followed by 6% (w / v) alginate (400 pg released) and 8% (w / v) alginate (300 pg) released. The cumulative release and release rate of hemoglobin is thus also in the presence of a basal PLA layer dependent on the alginate concentration within the layers of the segment. Fig. 8 : Variations of the height of the additional wall border (barrier) for impeding lateral diffusion of a polylactic acid (PLA) basal layer (wall thickness: 1 mm, wall height 0.3 mm). The basal layer (size 22 x 22 x 0,3 mm) was printed by a 3D-printing process (FFF technique). Within the basal layer periodic bumps were imprinted to increase the adhesion of the segments to the basal layer. (A) 3D-printing template of the basal layer, (B) to (D) light microscopic images of the basal layer from different angles (0.8x magnification).

[0161] Fig. 9 : Variations of the height of the additional wall border (barrier) for impeding lateral diffusion of a polylactic acid (PLA) basal layer (wall thickness: 0.46 mm, wall height 0.3 mm). The basal layer (size 22 x 22 x 0,3 mm) was printed by a 3D-printing process (FFF technique). Within the basal layer periodic bumps were imprinted to increase the adhesion of the segments to the basal layer. (A) 3D-printing template of the basal layer, (B) to (D) light microscopic images of the basal layer from different angles (0.8x magnification).

[0162] Fig. 10: Variations of the height of the additional wall border (barrier) for impeding lateral diffusion of a polylactic acid (PLA) basal layer (wall thickness: 0.46 mm, wall height 0.07 mm). The basal layer (size 22 x 22 x 0,3 mm) was printed by a 3D-printing process (FFF technique). Within the basal layer periodic bumps were imprinted to increase the adhesion of the segments to the basal layer. (A) 3D-printing template of the basal layer, (B) to (D) light microscopic images of the basal layer from different angles (0.8x magnification).

[0163] Fig.11 : Influence of wall height of the PLA basal layer on hemoglobin release rate from an alginate segment. The segments comprised 6% (w / v) alginate within the layers of the segment and in total 550 pg hemoglobin per segment. No increase of release rate was observed upon lower wall height (0.07 mm height compared to 0.3 mm height). A reduction of wall dimensions of the basal layer (wall height and wall thickness) did not change the function of the wall and basal layer, i.e., the decrease and impedance of lateral diffusion of hemoglobin. Overall, by including a basal layer within the composition the release of 75% of hemoglobin included in the alginate segment occurs within 24 h instead of 1 h as observed for an alginate segment without a basal layer.

[0164] Fig.12: Schematic overview of in vivo evaluation of the release of lysozyme from the composition implanted in the spinal cord in comparison to direct injection of lysozyme into the spinal cord. Mice were either directly injected with lysozyme into the spinal cord (positive control) or a composition in the form of a solid and planar implant comprising no lysozyme (negative control) or comprising lysozyme was implanted to the spinal cord. Longitudinal observation with neurological assessment was performed up to 28 days. Structural analyses were performed at 1 and 7 days after the composition was implanted. CW: Catwalk gait analysis, BMS: Basso Mouse Scale, MRT: magnetic resonance imaging; IHC: Immunohistochemistry, ELISA: Enzyme-linked Immunosorbent Assay.

[0165] Fig.13: Weight and basso mouse scale in mice after sham-surgery (placebo; Sham SCI) and after the composition is implanted to the spinal cord (Sham SCI_TE). No significant differences in body weight and locomotor skills measured by basso mouse scale were observed between sham-surgery and implantation of the composition to the spinal cord. Locomotor skills, assessed using the Basso Mouse Score (BMS), were rated with the highest score without exception (9). Fig.14: Catwalk gait analysis 7 days after implantation of the composition (Sham SCI Patch) or Sham-surgery (placebo, Sham SCI). No significant differences in gait were observed between Sham surgery and implantation of the composition.

[0166] Fig.15: Determination of the lysozyme content in the spinal cord post-implantation of the composition (lysozyme patch) and a placebo composition comprising no lysozyme (empty patch) by an ELISA. The majority of lysozyme is detected in the spinal cord 1 day after implantation of the composition (lysozyme patch), which is consistent with the in vitro data on the release. A lower amount of lysozyme is detected 7 days after implantation, whereas no release is observed after 28 days (similar to the empty patch comprising no lysozyme).

[0167] Fig. 16: Quantitative evaluation of the MRI analysis after the composition is implanted to the spinal cord. The volumetric analysis of the MRI images showed no change in spinal cord volume after implantation of the composition to the spinal cord, while the volume of the composition decreased significantly over 28 days. (* p < 0.05 , **** p < 0.0001 ).

[0168] Fig. 17: Quantitative evaluation of the immunohistochemistry (IHC)-analysis after a composition comprising lysozyme (Lysozyme patch) is implanted to the spinal cord compared to a composition comprising no lysozyme (blank patch). The analysis of the relative fluorescence intensity (RFI) showed an increase in RFI after implanting the Lysozyme patch, decreasing significantly over 28 days. This demonstrates that Lysozyme is released from the composition over time and remains detectable within the murine spinal cord up to one week post-implantation. No increase in RFI was observed after implanting the Blank patch. (**** p < 0.0001 ).

[0169] Fig. 18: Microparticles comprising lysozyme as a surrogate protein at a concentration of 10 wt% were prepared using a two-substance nozzle (left column for each value on the x-axis) or three- substance nozzle (right column for each value on the x-axis). Microparticle degradation time in aqueous solution is indicated in hours on the x-axis. Lysozyme concentration in the supernatant in mg / l is indicated on the y-axis.

[0170] Fig. 19 : GelMA (methacrylated gelatine) hydrogel A) with embedded microparticles (MP), wherein the microparticles comprise lysozyme as a surrogate protein and B) without embedded microparticles. MPs can be dispersed homogeneously in the hydrogel during the gelation process. The hydrogel with MPs (A) shows a homogeneous turbidity, while the MP-free hydrogel (B) is clear. C) Substance release profile from pure microparticles (MPs) and MPs embedded in GelMA (methacrylated gelatine) hydrogel. In comparison to lysozyme release from pure microparticles, lysozyme release from MPs embedded in hydrogel is strongly reduced and extended in time.

[0171] EXAMPLES

[0172] The invention is demonstrated by way of the examples disclosed herein. The examples provide technical support for a detailed description of potentially preferred, non-limiting embodiments of the invention.

[0173] Example 1 : In vitro protein release Methods

[0174] Segments and compositions (patches) of different biomaterial concentrations (alginate) as well as consisting of hard and soft matrix (polylactic acid (PLA) and alginate), comparing hemoglobin or lysozyme were 3D-printed via FFF using a commercially available but proprietarily modified 3D- printer. Alginate segments (native or hemoglobin laden) were fabricated by deposition of 125 pl of alginate solution onto a tissue culture plate, followed by 3 min exposure to CaCh-solution vapor and subsequent immersion in CaCh-solution. Segments and compositions (patches) measured 20 x 20 x 0.3 mm. For determination of release profiles, segments and compositions (patches) were immersed in a physiological buffer solution (HEPES-saline) and supernatants were analyzed for hemoglobin content after predetermined timepoints. Hemoglobin concentration in supernatants was determined by measuring the absorbance at 660 nm and plotting results against a standard curve of known concentrations.

[0175] Results

[0176] By varying the biomaterial concentration and hybridization with a hard matrix, temporal control of the release kinetics of a surrogate protein (lysozyme) from the segments and compositions (patches) were achieved. By increasing the biomaterial concentration and introducing a diffusionlimiting barrier layer (blocking layer and / or basal layer), the release of lysozyme could be extended from an initial release spurt of the majority of the introduced protein within the first 30 min to 24 hours. The results of the in vitro protein release form the compositions (patches) of the present invention are shown in Figures 2 to 1 1 .

[0177] Example 2: In vivo evaluation of compositions

[0178] Methods

[0179] Lysozyme release from alginate compositions (patches) was investigated in vivo following epidural implantation onto the murine spinal cord, compositions (patches) were fabricated as described above, brought to the operating room in sterile packaging and subsequently implanted following microsurgical laminectomy and adaptation of composition (patch) size to the laminectomy area. Animals were administered with buprenorphine subcutaneously during the operation and for three days afterwards. During the entire observation period, the animal weight and Basso mouse score (BMS) was determined daily. Catwalk gait analysis and MRI were performed on days 1 , 7 and 28 after implantation. To accustom the animals to the catwalk examination in advance, three runs were carried out with each animal on three different days in the week before implantation.

[0180] The Basso Mouse Scale (BMS) is a test for the assessment of locomotion in mice. It is sensitive, valid, and reliable for quantifying the recovery of locomotion after SCI. The paw movement was assessed and documented by two examiners in an open field on a scale from 0 (no paw movement) to 9 (normal gait pattern). Catwalk gait analysis is a complete gait analysis system for quantifying footfalls and locomotion in rats and mice. Test animals walked through a glass-floor tunnel and back thrice, with paw prints being recorded via camera. Base of support and hindlimb stride length (cm), speed and transition time (s), swing speed (cm / s), and hindlimb mean intensity (%) were recorded. Magnet resonance imaging (MRI) was performed using a 7 Tesla small animal MRI with a T2-Turbo RARE sequence. Axial and sagittal images were taken in each animal. Images were acquired using Paravision 6.0.1 software and then analyzed for spinal cord volume and patch volume using Horos v3.3.6 software. In addition, each animal was examined in the sagittal and axial images for potential edema in the spinal cord.

[0181] On days 1 , 7 and 28, n = 5 animals with alginate composition (alginate-patch) and alginate- lysozyme composition (alginate-lysozyme patch) were perfused intracardially with PBS solution. The spinal cord was removed, immediately shock-frozen in liquid nitrogen and stored at -80 °C. The section below the composition (patch) was divided and used to perform Enzyme-linked immunosorbent assay (ELISA) following homogenization and immunofluorescent staining (IF) following gelatin embedding.

[0182] Results

[0183] In vivo experiments showed that lysozyme released from the compositions (patch) is detectable in the spinal cord up to 7 days post implantation and that the implantation does not negatively affect test animals compared to the control.

[0184] At all time points, no deviations in weight, BMS or catwalk gait analysis (n = 16 per time point) were observed in animals with implanted composition (patch) compared to control animals without composition (patch). This indicates that gait pattern and general condition of the animals is not affected by the implantation of the composition (patch). Volumetric analysis of axial MRI images (n = 8 per time point) showed no changes in spinal cord volume throughout the study. Furthermore, no significant edema were observed in the spinal cord. The composition (patch) volume decreased significantly by approx. 40% over the course of the study. Lysozyme determination in explanted spinal cord segments revealed a high amount of lysozyme on the first day after implantation, followed by a lower but clearly detectable amount on day 7 compared to the control. On day 28, no difference in detected lysozyme was observed between the composition (patch) group with and without lysozyme. IF staining corroborated these results, showing strong lysozyme staining 24 hours post-implantation compared to the control group without lysozyme. After 7 days, the fluorescence was less clearly increased compared to the control group and on day 28 was no longer distinguishable. These results indicate a considerable release of lysozyme from the composition (patch) within the first 24 hours, which was significantly reduced in the first week and no longer detectable at an increased level after four weeks. The results of the in vivo evaluation the compositions (patches) of the present invention are shown in Figures 12 to 17.

[0185] Example 3: Protein release from microparticles

[0186] Methods

[0187] A surrogate protein (lysozyme) was encapsulated into microparticles using a two-substance nozzle or a three-substance nozzle. Lysozyme was released from the microparticles over several days into an aqueous solution by microparticle degradation.

[0188] Results Lysozyme was largely found in the supernatant. It is important to note that lysozyme has physicochemical properties similar to many therapeutically relevant neurotrophic factors. In view of this, this Example demonstrates the feasibility of encapsulation of a target therapeutic agent using this method and particle type. The actual release or particle degradation in tissue would, however, occur over considerably longer periods of time.

[0189] The result is shown in Fig. 18.

[0190] Example 4: Protein release from microparticles with or without microparticle embedding into hydrogel

[0191] Methods

[0192] A surrogate protein (lysozyme) was encapsulated into microparticles (MPs). Lysozyme-containing microparticles were homogeneously dispersed into methacrylated gelatine hydrogel (GelMA) and lysozyme release was compared with that of lysozyme-containing microparticles in an aqueous solution. MPs can be dispersed homogeneously in the hydrogel during the gelation process. Lysozyme release was quantified in PBS using an enzyme-linked immunosorbent assay (ELISA) to determine whether the enzymatic activity was retained. This Example serves to simulate the two-step release due to a first encapsulation into microparticles and a second embedding into a hydrogel.

[0193] Results

[0194] Enzyme effectiveness after encapsulation and release and in parallel with microparticle degradation could be confirmed. The lysozyme’s active center remained activated through encapsulation, which demonstrates the strong potential of secondary microparticle encapsulation also for further therapeutic agent classes relevant for medical conditions associated with a healing disorder, in particular spinal cord injury.

[0195] After three days, in the case of microparticles not embedded into a hydrogel, 74.9% of the incorporated lysozyme was released.

[0196] The microparticles sprayed with lysozyme can easily be dispersed in aqueous solutions and could be encapsulated at 1.25 wt% into a model hydrogel (GelMA - methacrylated gelatine). The agent lysozyme shows a delayed release. In contrast to pure MP powder (74.9% release, see above), only 28.8% of lysozyme were released after embedding into hydrogel after three days.

[0197] Hence, in comparison to lysozyme release from pure microparticles, lysozyme release from MPs embedded in hydrogel is strongly reduced and extended in time, which confirms the general feasibility of delayed release to 7 days.

[0198] The result is shown in Fig. 19. REFERENCES

[0199] Hodgetts, S. I., & Harvey, A. R. Neurotrophic factors used to treat spinal cord injury. Vitamins and hormones, 104, 405-457. (2017).

[0200] Ahuja, C. S., et al., Traumatic spinal cord injury — repair and regeneration. Neurosurgery, 80 (3S), S9-S22. (2017).

[0201] Alizadeh, A., Dyck, S. M., & Karimi-Abdolrezaee, S. Traumatic spinal cord injury: an overview of pathophysiology, models and acute injury mechanisms. Frontiers in neurology, 10, 282. (2019).

[0202] Silva, D., Sousa, R. A., & Salgado, A. J. Hydrogels as delivery systems for spinal cord injury regeneration. Materials Today Bio, 9, 100093. (2021).

Claims

CLAIMS1 . A composition configured for time and spatially controlled delivery of two or more therapeutic agents to a damaged tissue of a subject, characterized in that the composition is in a solid and planar form and comprises a basal layer, two or more segments attached to the basal layer and two or more therapeutic agents, wherein the two or more segments are horizontally arranged on the basal layer and are separated by a blocking layer, wherein the two or more segments comprise one or more polymer layers, wherein a first polymer layer is attached to the basal layer and one or more further polymer layers are vertically stacked on to the first polymer layer, and each of the two or more segments comprises one or more of the therapeutic agents in at least one polymer layer.

2. The composition according to claim 1 , wherein the basal layer, the blocking layer and the one or more polymer layers comprise one or more biodegradable polymers.

3. The composition according to any one of the preceding claims, the basal layer and the blocking layer are impermeable for the two or more therapeutic agents.

4. The composition according to any one of the preceding claims, wherein the composition is prepared by a 3D-printing process comprising 3D-printing of the basal layer, the blocking layer and the two or more segments.

5. The composition according to any one of the preceding claims, wherein the one or more biodegradable polymers are selected from the group consisting of collagen or a derivative thereof such as gelatin, methacrylated collagen (ColMA) or methacrylated gelatin(GelMA), polyethylene glycol diacrylate(PEGDA), alginate or a derivative thereof such as methacrylated alginate, polycaprolactone (PCL), poly lactic acid (PLA), poly(lactic-co-glycolic acid)(PLGA), methacrylated hyaluronic acid, chitosan and cellulose derivatives such as carboxymethylcellulose and agarose.

6. The composition according to any one of the preceding claims, wherein the two or more segments comprise 1 to 20 polymer layers, preferably 2 to 15, more preferably 5 to 10.

7. The composition according to any one of the preceding claims, wherein one or more of the segments comprises at least two polymer layers, wherein a. the two or more polymer layers each comprise one or more of the therapeutic agents and wherein the concentration of the one or more therapeutic agents is increasing with each polymer layer stacked onto the first polymer layer, with the polymer layer most distant from the basal layer comprising the highest concentration of the one or more therapeutic agents, b. the two or more polymer layers alternately comprise one or more of the therapeutic agents or no therapeutic agent, orc. at least the first polymer layer comprises one or more of the therapeutic agents and at least the layer most distant from the basal layer comprises no therapeutic agent.

8. The composition according to any one of the preceding claims, wherein one or more of the segments comprises at least two polymer layers, wherein the concentration of the biodegradable polymer in the two or more polymer layers is increasing with each polymer layer stacked onto the first polymer layer, with the polymer layer most distant from the basal layer comprising the highest concentration of the biodegradable polymer.

9. The composition according to any one of the preceding claims, wherein the one or more polymer layers comprise a crosslinked biodegradable polymer with a degree of crosslinking of 50 to 100 %, preferably 65 to 90 %, more preferably 80 to 90 %.

10. The composition according to any one of the preceding claims comprising three or more segments.

11. The composition according to any one of the preceding claims, wherein one or more of the segments additionally comprises a ring-shaped blocking layer, wherein the ring- shaped blocking layer is impermeable for the two or more therapeutic agents.

12. The composition according to any one of the preceding claims, wherein the two or more therapeutic agents are selected from the group consisting of a neurotrophic growth factor, an anti-inflammatory agent, an inhibitor of neurodegeneration and an inhibitor of glia scar formation.

13. The composition according to any one of the preceding claims, wherein a. the one or more polymer layers each have a thickness of 50 to 300 pm, preferably 75 to 200 pm, more preferably 100 to 150 pm. b. the blocking layer has a thickness of 100 to 500 pm, preferably 150 to 400 pm, more preferably 200 to 300 pm, and / or c. the basal layer has a thickness of 100 to 600 pm, preferably 200 to 500 pm, more preferably 300 to 400 pm.

14. The composition according to any one of the preceding claims, wherein the blocking polymer layer and / or the basal layer comprise polylactic acid (PLA), polycaprolactone (PCL), polylactid-co-glycolide (PLGA) and / or a mixture thereof.

15. Composition according to any one of the preceding claims for use in the treatment of a medical condition associated with a healing disorder.

16. Composition for use according to the preceding claims, wherein the medical condition associated with a healing disorder is selected from the group consisting of central nervous system (CNS) disease, traumatic brain injury, spinal cord lesion, a peripheral nerve injury, ischemic nerve injury, stroke, and a healing disorder associated with a metabolic disorder.

17. Composition for use according to claims 16 and 17, wherein the medical condition associated with a healing disorder is a spinal cord injury.

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