23 Jul IN VITRO OR IN VIVO GELFYING CHITOSAN AND THERAPEUTIC USES THEREOF
Abstract
The present invention relates to composition, method and applications of loaded or unloaded Chitosan-.beta.-Glycerophosphate hydrogels are proposed for cosmetic, medical and surgical applications. Solid .beta.-Glycerophosphate is added and dissolved at low positive temperature (10.degree.C) within 0.5 to 3.0% w/v Chitosan in aqueous acidic solutions. The aqueous Chitosan-.beta.-Glycerophosphate solutions, initially stored at low positive temperatures, preferentially at 4.degree.C, are endothermally gelated within the temperature range of 30 to 60.degree.C, preferentially at 37.degree.C. The said Chitosan-.beta.-Glycerophosphate solution spontaneously transforms into a gel at the desired gelation temperature. Gelation can be ex vivo within any receivers or molds, or in situ in animals or humans so as to fill a tissue defect or cavity. Encapsulation of living cells or cellular matters is carried out by incorporating the said cells or cellular matters within the aqueous Chitosan-.beta.-Glycerophosphate solution at a low positive temperature (ideally at 4.degree.C), then by gelating the cells loaded Chitosan-.beta.-Glycerophosphate solution at the selected gelation temperature (ideally at 37.degree.C). Chitosan-.beta.-Glycerophosphate hydrogels without encapsulated living cells are selected for surgical reconstructive and regeneration uses and drug delivery purposes. Chitosan-.beta.-Glycerophosphate with encapsulated living cells are applied to the culture and engineering of artificial tissues as well as to the reconstruction of tissues. Engineering and regeneration of articular cartilage and cartilageous tissues are targeted through the injection and in situ gelation or the implantation of chondrogenic cells loaded in Chitosan-.beta.-Glycerophosphate systems.
Year: 1999
Country: CA
Doc No: 2212300