OBJECTIVETo describe the methods which were used to develop collagen-based materials for wound dressing.

METHODSFresh frozen bovine tendon was treated with 0.05 mol/L acetic acid at pH 3.2 for 48-72 hours, homogenized, filtered, mixed with 8% chondroitin sulphate, for creating a deaerated 1.5%-2.5% collagen solution. The solution was lyophilized in either a pre-frozen or non-pre-frozen mould. The collagen sponge was then cross-linked with 0.25% glutaraldehyde for 24 hours. Three other types of wound dressings were developed using a similar method: collagen membrane with a polyurethane membrane onlay, polyurethane-coated collagen membrane and collagen membrane on gauze.

RESULTSIt was demonstrated that the use of frozen bovine tendon was stable, and that the prepared collagen sponge contained pores of 50-400 microm in diameter.

CONCLUSIONSCollagen could be used as wound dressing.

Amino Acids ; analysis ; Animals ; Biological Dressings ; Cattle ; Collagen ; analysis ; chemistry ; isolation & purification ; Freeze Drying ; Polyurethanes

As a novel post-translational modification(PTM),lysine 2-hydroxyisobutyrylation(Khib)is considered to regulate gene transcriptional activities in eukaryotic cells;however,the functions of Khib-modified proteins in plants remain unknown.Here,we report that Khib is an evolutionarily-conserved PTM in wheat and its progenitors.A total of 3348 Khib sites on 1074 proteins are iden-tified in common wheat(Triticum aestivum L.)by using affinity purification and mass spectroscopy of 2-hydroxyisobutyrylome.Bioinformatic data indicate that Khib-modified proteins participate in a wide variety of biological and metabolic pathways.Immunoprecipitation confirms that Khib-modified proteins are present endogenously.A comparison of Khib and other main PTMs shows that Khib-modified proteins are simultaneously modified by multiple PTMs.Using mutagenesis experiments and co-immunoprecipitation assays,we demonstrate that Khib on K206 of phospho-glycerate kinase(PGK)is a key regulatory modification for its enzymatic activity,and mutation on K206 affects the interactions of PGK with its substrates.Furthermore,Khib modification of low-molecular-weight proteins is a response to the deacetylase inhibitors nicotinamide and tricho-statin.This study provides evidence to promote our current understanding of Khib in wheat plants,including the cooperation between Khib and its metabolic regulation.