No abstract

Nanoparticles based drug delivery systems showing greater potential in various biomedical applications to deliver the drugs/bioactive molecules in controlled manner to the targeted site. Polycaprolactone, biodegradable polyester, owing its tailorable properties, various forms of polycaprolactone are used as drug carrier for a range of biomedical applications. Nanoprecipitation is a simple method to prepare the polycaprolactone nanoparticles to improve the bioavailability and therapeutic potential of various drugs/bioactive molecules. This short review focused on the preparation of polycaprolactone nanoparticles using nanoprecipitation method, nanoparticles-drug formulations and its use in various drug delivery applications.

It is concluded that the receptor occupancy-response relationship is very similar for insulin and antibodies, in terms of the efficiency of coupling of occupied receptor to the signalling pathway which determines metabolic responses. However, this signalling pathway does not require autophosphorylation of receptors in the case of activation by anti-receptor antibodies. Indeed antibody 25-49 had no detectable effect on receptor phosphorylation in situ, even at a concentration 100 x higher than that required for maximum metabolic stimulation. Insulin under the same conditions dramatically increased receptor phosphorylation so that a response amounting to 1/20 of the maximum insulin effect could have been easily detected.The autophosphorylation of solubilized, purified receptor from both NIH 3T3 H1R3.5 and CHO-T cells was stimulated by those antibodies tested (83-7 and 18-44) in a manner very similar to that previously documented with placental receptor [9]. Presumably, the receptor in intact cells is subject to steric constraints or interactions with other proteins, which are not present in solubilized preparations, and which prevent autophosphorylation of the antibody-activated receptor.A mutant insulin receptor lacking kinase activity did not mediate the insulin-like effect of antibodies (25-49, 83-14 and 18-44) on glucose uptake when transfected into CHO cells [13]. It is indeed surprising that metabolic effects of antibodies apparently require a receptor with kinase activity, but do not involve autophosphorylation of the receptor which generally follows activation of this kinase. The explanation for this paradox is not at present clear. It is possible that effects of antibodies involve the increased internalization of a basally active receptor kinase, or the stimulation of kinase activity towards exogenous substrates without accompanying autophosphorylation. The study of further receptor mutants should help to define more precisely the structural features of receptors required to mediate metabolic responses to insulin and antibodies.We are very grateful to Drs R. Roth, L. Ellis, W. J. Rutter and J. Whittaker for the gift of transfected cell lines. We also thank the Medical Research Council, the Wellcome Trust and Serono Diagnostics Ltd for financial support. I , Ilcnton, R. M. ( I 986) Adv.

A biodegradable three-dimensional scaffolds have gathered attention and are widely studied for bone tissue engineering applications. In the present study, porous polycaprolactone scaffold entrapped with naringin loaded bovine serum albumin nanoparticles (PS-N-BSANP) has been engineered. Further, the prepared nanoparticles and interconnected porous scaffolds were characterized by scanning electron microscopy, X-ray diffraction and fourier transform infrared spectroscopy analysis. X- ray diffraction showed amorphization of naringin in PS-N-BSANP. In addition, sustained naringin release profile was observed from PS-N-BSANP for 12 days which showed a cumulative release of 52.54 micromolar (µM). Furthermore, conditioned medium from PS-N-BSANP showed an increased calcium deposition and collagen matrix formation under osteogenic conditions with C3H10T1/2 cell line. These results suggest that PS-N-BSANP enhanced the osteogenic differentiation potential in bone tissue engineering applications due to the controlled release of naringin.