Crosslinking of poly(N-vinyl pyrrolidone-co-n-butyl methacrylate) copolymers for controlled drug delivery

An injectable poly(caprolactone trifumarate-gelatin microparticles) (PCLTF-GMPs) scaffold for irregular bone defects: Physical and mechanical characteristics

Recently, a modified form of a three-dimension (3D) porous poly(caprolactone-trifumarate) (PCLTF) scaffold has been produced using a fabrication technique that involves gelatin microparticles porogen leaching. This poly(caprolactone trifumarate-gelatin microparticles) (PCLTF-GMPs) scaffold has been shown to be biocompatible, more flowable clinically, and has a shorter degradation time as compared to its existing predecessors. In this report, a detailed characterization of this new scaffold was performed by testing its cytocompatibility, analyzing the surface topography, and understanding its thermal, physical and mechanical properties. The result showed that the PCLTF-GMPs has no critical cytotoxic effect. To confirm improvement, the surface properties were compared against the older version of PCLTF fabricated using salt porogen leaching. This PCLTF-GMPs scaffold showed no significant difference (unpaired t-test; p>0.05) in mechanical properties before and after gelatin leaching. However, it is mechanically weaker when compared to its predecessors. It has a high biodegradability rate of 16weeks. The pore size produced ranges from 40 to 300μm, and the RMS roughness is 613.7±236.9nm. These characteristics are condusive for osteoblast in-growth, as observed by the extension of filopodia across the macropores. Overall, this newly produced material has good thermal, physical and mechanical properties that complements its biocompatibility and ease of use.

Copolymerization of Tris(methoxyethoxy)vinyl Silane with N-Vinyl Pyrrolidone: Synthesis, Characterization, and Reactivity Relationships

Copolymer of tris(methoxyethoxy)vinyl silane (TMEVS) with N-vinyl pyrrolidone (NVP) was synthesized by free radical polymerization in dry benzene at 70°C using benzoyl peroxide (BPO) as initiator. The copolymer was characterized by viscometer, FTIR, and1H-NMR and its thermal properties were studied by DSC and TGA. The copolymer composition was determined by elemental analysis. The monomer reactivity ratios were calculated by linearization methods proposed by Fineman-Ross and Kelen-Tudos. The intersection method was proposed by Mayo-Lewis and nonlinear method was proposed by curve-fitting procedure. The microstructure of copolymer and sequence distribution of monomers in the copolymer were calculated by statistical method.