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Biological Compatibility Profile on Biomaterials for Bone Regeneration
Published on: November 16, 2018
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In situ foamable, degradable polyurethane as biomaterial for soft tissue repair
Thorsten Laube1, Jürgen Weisser1, Stefan Berger1
1INNOVENT e.V., Biomaterials Department, Jena, Germany.
Summary
New biodegradable foams, created from (l-lactide-co-ε-caprolactone), can be endoscopically delivered as liquids to seal tissue defects. These in situ foaming materials show excellent cytocompatibility and degrade into connective tissue, offering promising surgical applications.
Area of Science:
- Biomaterials Science
- Polymer Chemistry
- Surgical Innovation
Background:
- Degradable foams offer potential for endoscopic treatment of soft tissue defects.
- In situ foaming and expansion can seal defects effectively.
- Current treatments may have limitations in defect sealing and biocompatibility.
Purpose of the Study:
- To develop and characterize an in situ foamable, degradable prepolymer for soft tissue defect repair.
- To evaluate the foaming, mechanical, and cytocompatibility properties of the developed material.
- To assess the in vivo performance and degradation of the foam in a preclinical model.
Main Methods:
- Synthesis of a star-shaped (l-lactide-co-ε-caprolactone) prepolymer via ring-opening polymerization.
- Modification of hydroxyl end-groups with lysine diisocyanate ethyl ester (LDI) to create a reactive prepolymer.
- Initiation of in situ foaming and curing using additives like 1,4-diazabicyclo[2,2,2]octane (DABCO), water, LDI, and DMSO.
- Characterization of foam porosity, tensile strength, and elongation.
- In vitro cytotoxicity testing on 3T3 fibroblasts and in vivo evaluation in a rat subdermal incision model.
Main Results:
- A reactive, isocyanate-endcapped prepolymer was successfully synthesized.
- Foaming and curing times were adjustable within a clinically relevant range by varying additive composition.
- The resulting foams exhibited ~90% porosity, 0.3 MPa tensile strength, and 90% elongation.
- Excellent in vitro cytocompatibility was observed with 3T3 fibroblasts.
- In vivo studies showed minimal chronic inflammation, vascularization, degradation, and substitution by connective tissue in both prefabricated and in situ foamed materials.
Conclusions:
- The developed in situ foamable (l-lactide-co-ε-caprolactone)-based material demonstrates promising properties for soft tissue defect repair.
- The material exhibits good mechanical characteristics, excellent cytocompatibility, and predictable in vivo degradation.
- Further investigation in more heavily loaded defects is warranted based on these encouraging results.
