Remineralization of partially demineralized dentine substrate based on a biomimetic strategy

10.1007/s10856-012-4550-5Journal of Materials Science: Materials in Medicine233733-742JSMM

Fabrication of asymmetric membranes from polyhydroxybutyrate and biphasic calcium phosphate/chitosan for guided bone regeneration

[[abstract]]Chitosan (CS) is known for its biocompatibility, antibacterial function, and wound healing acceleration, while calcium phosphate (CP) can promote bone regeneration. However, to be useful as barrier membrane for guided bone regeneration (GBR) in periodontal treatments, the membranes must have suitable mechanical strength in addition to good barrier properties. Therefore, a dense polyhydroxybutyrate (PHB) layer was integrated with a porous biphasic calcium phosphate/chitosan (BCP/CS) layer to form an asymmetric PHB-BCP/CS membrane. Moreover, for enhancing the interfacial strength, the PHB layer was chemically bonded to the BCP/CS layer through plasma-induced grafting of poly(acrylic acid) on its surface and followed by amidation with CS via carbodiimide activation. The incorporation of the PHB layer greatly increased the initial modulus and ultimate tensile strength of the membrane up to 524 and 16.5 MPa, respectively. In addition, the human gingival fibroblast (HGF) cells could proliferate very well on the PHB layer of the membrane, yet they were prohibited from down-growing through the membrane. Also, the addition of BCP particles in the CS layer increased the proliferation of osteoblast cells. Thus, the asymmetric PHB-BCP/CS membrane has the potential to be used as a barrier membrane for GBR in periodontal tissue engineering.[[incitationindex]]SCI[[booktype]]紙

Use of Chitosan as a Bioactive Implant Coating for Bone-Implant Applications

Chitosan is the deacetylated derivative of the natural polysaccharide, chitin. Chitosan has been shown to be biocompatible, biodegradable, osteoconductive, and to accelerate wound healing. These characteristics are largely due to its structural and chemical homology to hyaluronic acid and other proteoglycans found in extracellular matrices. Because of these properties, chitosan has been investigated as a coating for implant materials to promote osseointegration, and as a potential vehicle to deliver therapeutic agents to the local implant-tissue interface. The coating of chitosan onto implant alloy surfaces has been achieved via chemical reactions and electrodeposition mechanisms as well as by other methods such as dip coating and layer-by-layer assembly. This work examines the different mechanisms and bond strengths of chitosan coatings for implant alloys, coating composition and physiochemical properties, degradation, delivery of therapeutic agents, such as growth factors and antibiotics, and in vitro and in vivo compatibilities. © 2011 Springer-Verlag Berlin Heidelberg