Effects of surface properties of bacterial poly(3-hydroxybutyrate-co-3-hydroxyvalerate) on adhesion and proliferation of mouse fibroblasts

Biocompatible and functional properties of a microdispersed tissue-specific 3D matrix from decellularized porcine cartilage

In contrast to decellularization of soft tissues for use as tissue-specific matrices in the creation of tissue-engineered constructs, decellularization of cartilage tissue requires several processing techniques, which can negatively affect the biocompatibility and functional properties of the native extracellular matrix (ECM).

Objective: to study the biocompatible and functional properties of microdispersed tissue-specific 3D matrix from a porcine cartilage that is decellularized by sequential use of chemical, physical and enzymatic techniques.

Materials and methods. For decellularization, microdispersed cartilage particles (MCPs), obtained by cryomilling, were incubated in detergent solutions (sodium dodecyl sulfate and Triton X-100), then treated with supercritical carbon dioxide (scCO2) with 10% ethanol and DNase I. The Ames test (Salmonella typhimurium reverse mutation assay) was used to determine the genotoxicity of decellularized microdispersed cartilage particles (dMCPs). Local and general toxic effects, as well as resorption of dMCPs were studied in vivo on sexually mature outbred rats. Decellularized MCP specimens (10 mg) were implanted into the thigh muscle tissue. Viability of human adipose-derived mesenchymal stem/stromal cells (hAdMSCs), when cultured on dMCPs, was analyzed by in vivo microscopy, stained with fluorescent Calcein AM dye. Cell metabolic activity was assessed using PrestoBlue™ Cell Viability Reagent.

Results. It has been proven that porcine dMCPs implanted in rat muscle after treatment with scCO2 do not exhibit local and general toxic effects, and do not show genotoxicity and negative effects on the reproductive system of animals. After 6 months of in vivo experiment, most (87%) of the implanted decellularized cartilage was resorbed. It was shown that the resulting matrices are able to support adhesion and proliferation of hAdMSCs. Conclusion. Porcine dMCP specimens are suitable for biocompatible medical products in terms of local and general toxic effects, genotoxicity and reproductive toxicity, and can be used as a matrix for creating cell- and tissue-engineered cartilage constructs.

Biocompatibility of polyhydroxybutyrate-co-hydroxyvalerate films generated from Bacillus cereus MCCB 281 for medical applications

Polyhydroxyalkanoates (PHAs) are natural polyesters produced by microorganisms as a source of intracellular energy reserves. These polymers have been extensively studied for tissue engineering and drug delivery applications due to their desirable material properties. Solvent-cast film of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), produced by Bacillus cereus MCCB 281 was characterized to study the surface morphology, roughness, thermal and mechanical properties. PHBV films were slightly hydrophilic with an average surface roughness of 43.66 nm. In vitro cell viability and proliferation studies on PHBV film surface investigated using L929 fibroblasts showed good cell attachment and proliferation. Hemocompatibility of PHBV evaluated by hemolysis assay, in vitro platelet adhesion and coagulation assays demonstrated good blood compatibility for use as blood contact graft materials. Therefore, PHBV produced from the marine bacterium favoured cellular growth of L929 fibroblasts indicating its potential to be used as a biomaterial substrate for cell adhesion in tissue engineering and medical applications.