Hidrólise seletiva de carboxiamidas de resíduos de asparagina e glutamina em colágeno: preparação e caracterização de matrizes aniônicas para uso como biomateriais

Abstract

BIOMATERIAL APPLICATIONS. This work describes the selective hydrolysis of carboxyamide groups of asparagine and glutamine of collagen matrices for the preparation of negatively charged collagen biomaterials. The reaction was performed in the presence of chloride and sulfate salts of alkaline and alkaline earth metals in aqueous dimethylsulfoxide solution and, selectively hydrolysis of carboxyamide groups of collagen matrices was promoted without cleavage of the peptide bond. The result is a new collagen material with controlled increase in negative charge content. Although triple helix secondary structure of tropocollagen was preserved, significative changes in thermal stabilities were observed in association with a new pattern of tropocollagen macromolecular association, particularly in respect microfibril assembly, thus providing at physiological pH a new type of collagen structure for biomaterial preparation, characterized by different charge and structural contents .

Interaction of anionic collagen with chitosan: Effect on thermal and morphological characteristics

“…Anionic collagen was obtained by the treatment of porcine serosa in aqueous alkaline solution (pH 13), for periods ranging from 24 to 96 h. In short, porcine serosa was treated at 20°C with an alkaline solution (3 mL/g of tissue) containing salts (chlorides and sulfates) of alkaline (K + and Na + ) and alkaline earth metals (Ca +2 ) as described earlier (Lacerda, Plepis, & Goissis, 1998). The material was suspended in deionized water, the pH adjusted with acetic acid (pH 3.5) and stored under refrigeration (4°C).…”

Determinação da energia de ativação em hidrogéis poliméricos a partir de dados termogravimétricos

“…O colágeno aniônico foi obtido por tratamento de tendão bovino com uma solução alcalina contendo cloretos e sulfatos de sódio, potássio e cálcio durante 24 horas [12] . O material foi suspenso em água desionizada e o pH ajustado para 3,5 com ácido acético e mantido sob refrigeração (4 °C).…”

Clinical evaluation and induced corneal vascularization study by native and anionic collagen membranes in rabbits corneas

“…The NCM and ACM were manufacture and supplied by Biochemical and Biomaterial Laboratory of the Chemical Institute of São Paulo University -USP -São Carlos, Brazil (10)(11) .…”