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Central Leather Research Institute (Council of Scientific and Industrial Research),Sardar Patel Road, Adyar, Chennai 600 020, IndiaReceived 11 January 2012; revised 30 August 2012; accepted 5 October 2012Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jbm.b.32856Abstract: A biodurable porous scaffold of collagen withgood biocompatibility and enhanced wound healing poten-tial is prepared through casting technique using tannic acid(TA) as crosslinker. The morphological analysis of the tannicacid cross-linked collagen scaffold (TCCs) distinctively showsscaly interlinks with large pores. The enzymatic stability ofthe scaffold is characterized in vitro to detail the role of TAin stabilization of collagen matrix against collagenolytic deg-radation. TCCs shows more stability (>54%) against collage-nase than that of the collagen scaffolds (Cs). The attenuatedtotal reflectance Fourier transform infrared analysis of theTCCs confirms the noncovalent interaction between collagenand TA. The biocompatibility of the scaffold (TCCs) in vitrohas been established using 3T3 fibroblasts. Therapeutic andwound healing potential of the TCCs has been studied invivo using excision wound model in rats. The results clearlyindicates that the TCCs has greater and significant effect inwound closure and increased the wound healing rate com-pared with native Cs. This biocompatible and biodurablescaffold may find broad applications in the tissue engineer-ing and drug delivery applications.

Poly(caprolactone) (PCL) electrospun nanofibers were modified by aminolysis and collagen was immobilized on the aminolysed PCL nanofibers. Considering low immunogenic response collagen elicits, immobilization of the same is anticipated to enhance the tissue engineering application of the PCL nanofibers. Amino groups were introduced into PCL nanofibers through aminolysis process. Aminolysis of PCL nanofibers was confirmed by electron dispersive X-ray analysis (EDX). Collagen was immobilized on aminolysed PCL nanofibers using glutaraldehyde as crosslinker. The collagen crosslinking on to PCL nanofibers was established by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The fiber morphologies of PCL nanofibers at different stages were characterized by scanning electron microscopy (SEM). The change in hydrophobicity of PCL nanofibers due to aminolysis and collagen immobilization was determined by water contact angle measurements. Aminolysis followed by collagen immobilization had reduced the intrinsic hydrophobicity of PCL nanofibers. NIH 3T3 fibroblasts were cultured for 2 days on PCL nanofibers, aminolysed PCL nanofibers, and aminolysed PCL nanofibers crosslinked with collagen. Cell attachment and growth were observed by MTT assay in each case. Collagen immobilization improved the biocompatibility of the PCL nanofibers. Thus the modified PCL nanofibers can be used as suitable broad spectrum scaffold for skin, cartilage, bone, cardiac constructs for efficient tissue engineering applications.

The central role of collagen as the major structural fibrous protein in the mammalian extracellular matrix has motivated a significant effort toward the determi- nation of its mechanical properties at all levels, ranging from single monomers and long-chain polymers to a structural element within a biological tissue. However, the stabiliza- tion of collagen against collagenolytic degradation finds sig- nificance in biomedical and industrial applications. Tannins are plant-derived polyphenols that have the ability to inhibit the collagenase activity at minimum concentration. The in- hibitory effect of wattle (Acacia mollissima) and myrobalan (Terminalia chebula) on the action of collagenase against colla- gen was probed in this study. The kinetics of the inhibition of collagenase by wattle and myrobalan was deduced from the extent of hydrolysis of 2-furanacryloyl-L-leucyl-glycyl- L-prolyl-L-alanine. Both wattle and myrobalan tannin exhib- ited competitive modes of inhibition against collagenase. Circular dichroism studies of collagenase on treatment with wattle and myrobalan revealed changes in the secondary structure of collagenase. These results suggest that the tan- nins of A. mollissima and T. chebula extracts facilitated colla- gen stabilization through collagenase inhibition. 2007

Brown seaweed (Turbinaria spp) was pre-treated with sulfuric acid, calcium chloride and magnesium chloride and tested for its ability to remove chromium from tannery wastewater. Protonated seaweeds gave better uptake of chromium compared with calcium and magnesium treatments. Chromium uptake was optimal at pH 3.5. Turbinaria weed exhibited maximum uptake of about 31 mg of chromium for one gram of seaweed at an initial concentration of 1000 ppm of chromium. Freundlich and Langmuir adsorption isotherm models were used to describe the biosorption of chromium(III) by Turbinaria spp. The chromium-loaded seaweed was reused as a reductant in the preparation of the tanning agent basic chromium sulfate (BCS). Leathers made from this tanning agent had properties comparable to conventionally processed chrome-tanned leathers. Copyright © 2004 Society of Chemical Industry