Biodegradable Pressure Sensitive Adhesive for Tissue Bonding
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Solution Overview
Problem
Conventional pressure sensitive adhesives based on acrylic polymers are not biodegradable and biocompatible enough for applications involving biological tissues, limiting their use in vivo.
Innovation Solution
A biodegradable composition is developed, comprising the reaction product of an isocyanate group-containing component and an active hydrogen group-containing component, which can be either permanently tacky or slow-curing, allowing for pressure sensitive adhesive properties at body temperature and humidity, suitable for bonding with biological tissues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acrylic polymers and copolymers are used as pressure sensitive adhesives, then adhesive performance is achieved, but biodegradability and biocompatibility are insufficient for in vivo use
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive by using biodegradable polymers (polyesters, polycaprolactone, polyglycolic acid) instead of conventional acrylic polymers. This parameter change maintains pressure sensitive adhesive properties while adding biodegradability and biocompatibility, enabling safe in vivo use.
Solution Approach 2:
The patent creates composite adhesive formulations by combining biodegradable polymer base resins with specific additives including tackifiers (rosin, coumarone-indene), plasticizers (phthalates, citrates), and fillers. This composite approach maintains the necessary adhesive performance characteristics while the biodegradable base polymer ensures biocompatibility and biodegradability for medical applications.
2Object-affected harmful factors
If biodegradable polyesters are used for in vivo pressure sensitive adhesives, then biocompatibility is improved, but adhesive performance and repositionability are reduced
Solution Approach 1:
The patent adjusts key adhesive parameters by incorporating tackifiers (5-20% by weight) to increase initial tack, plasticizers (10-30% by weight) to maintain flexibility and repositionability, and controlling the glass transition temperature of the polymer matrix. These parameter adjustments enable biodegradable polymers to achieve adequate adhesive performance while maintaining repositionability for surgical mesh application.
Solution Approach 2:
The patent formulates composite adhesive systems using biodegradable polymer base resins combined with specific ratios of tackifiers, plasticizers, and fillers. This composite formulation compensates for the inherently lower adhesive strength of biodegradable polymers by leveraging the synergistic effects of multiple components, achieving both biocompatibility and sufficient adhesive performance.
3Strength
If pressure sensitive adhesive is applied to bond mesh to tissue, then bonding is achieved, but repositionability is lost
Solution Approach 1:
The patent creates a dynamic adhesive system where the polymer matrix remains sufficiently soft and compliant at body temperature to allow mesh repositioning during surgery, yet provides adequate bonding strength once positioned. The plasticizers and low glass transition temperature ensure the adhesive remains dynamic and repositionable during the surgical procedure.
Solution Approach 2:
The patent carefully controls the glass transition temperature (Tg) of the adhesive formulation to be below body temperature, ensuring the adhesive remains in a rubbery, repositionable state during surgical application. The balance of polymer molecular weight, tackifier content, and plasticizer ratio creates optimal parameters for both initial repositionability and final bonding strength.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The composition effectively adheres to biological tissues, offering repositionability and eventual bonding while being biodegradable, addressing the limitations of existing adhesives in biocompatibility and biodegradability.
Implementation Method 1
the reaction product of: (a) an isocyanate group-containing component having an average functionality of at least 2; and (b) an active hydrogen group-containing component having an average functionality of at least 2
Implementation Method 2
has pressure sensitive adhesive properties at a temperature of 37° C. and 100% relative humidity
Data Source
AI summary
A method of making a composition comprising reacting (a) an isocyanate group-containing component having an average functionality of at least 2; and (b) an active hydrogen group-containing component having an average functionality of at least 2 to form a composition that is biodegradable, a solid at 22° C. and below, and has pressure sensitive adhesive properties at a temperature of 37° C. and relative humidity of 100%. A method of using the composition therefore to adhere polymer meshes or films to biological tissue is also disclosed.