A new collagen solution with high concentration and collagen native structure perfectly preserved

Abstract

Collagen, the most abundant protein in mammals, is widely used for making biomaterials. Usually, organic solvents, such as 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), or acids (H 3 PO 4 , HAc ) have been used to disperse collagen to make collagen-based biomaterials. However, the native structure of collagen has been often seriously damaged and the concentration of collagen in solutions was constantly relatively low, which greatly limited its application. In this research, we have firstly made a detailed study of the effect of H + and HAc on collagen dispersing in terms of Zeta potential, particle size and Circular Dichroism (CD), after that a benign sodium acetate/acetic acid buffer solution is proposed to disperse collagen. The results showed that the collagen solution from NaAc/HAc buffer solution at pH=3.0 had the suitability of both high concentration (100mg/mL) and perfect native structure preservation (up to 94%). We demonstrated that it was the constant concentration of free H + in the NaAc/HAc buffer solution whose pH was fixed at 3.0 that can maintain the amount of surface charges on the collagen colloidal particles unchanged, which makes collagen dispersed well even in high dose. As an application, the collagen solution from NaAc/HAc solution at pH 3.0 was successfully electrospun into nanofibers, and the obtained collagen nanofibers still can keep as much as 57% of its native structure. This study indicated that the novel buffer solution of NaAc/HAc at pH 3.0 would be commonly used in the processing of collagen for a variety of biomaterials based on collagen solution, which had great potential for use in tissue engineering.

Physicochemical changes of pepsin-solubilized and insoluble collagen in jumbo squid (Dosidicus gigas) muscle after cooking process

“…[40,43] The bands seen at around 3270, 2960 and 2930 cm −1 are related to N-H stretching. [44] It has been reported that the preservation degree of the triple hélix can be measured by the ratio between the amide III N-H absorbance and the C-N stretching of the proline ring (A1235/A1452), where a value of 1 indicates that the helix is preserved, while a decrease in this value is related to protein denaturation. [42,44,45] Therefore, based on the above evidence, the cooking process of fins and arms did not have an effect on the integrity of the collagen triple helix.…”

“…[44] It has been reported that the preservation degree of the triple hélix can be measured by the ratio between the amide III N-H absorbance and the C-N stretching of the proline ring (A1235/A1452), where a value of 1 indicates that the helix is preserved, while a decrease in this value is related to protein denaturation. [42,44,45] Therefore, based on the above evidence, the cooking process of fins and arms did not have an effect on the integrity of the collagen triple helix. However, displacements in the amide I and II bands at 1649-1645 and 1533-1526 cm −1 , respectively, and a displacement along with a decrease in the absorbance of the characteristic band of amide III (≈1240 cm −1 ) are shown in the spectra measured on the fractions extracted from the cooked muscle.…”

Solution fibre spinning technique for the fabrication of tuneable decellularised matrix-laden fibres and fibrous micromembranes

“…are commonly used for dissolving collagen I and gelatin materials to produce an electrospinnable solution [26], HFP leads to significantly degraded secondary and tertiary protein structures, which are undesirable [28,29]. In our method, water-based solvents with a mixture of acetic acid and ethyl acetate were chosen, where both reagents are known to have lower toxicity than HFP (LD50 for rats is 3310 mg/kg for acetic acid [30] and 5620 mg/kg for ethyl acetate [31], in comparison to 1500 mg/kg for HFP [32]).…”

Investigation on the interaction of collagen molecules in solution with different acetic acid concentrations

“…It is well known that AA at concentrations of 0.1–0.5 M is a common solvent for dissolving lyophilized collagen with the final release of molecules . However, the low CAC value and the weak fluidity of the collagen solution are the major drawbacks encountered in this AA concentration range, which affects the manufacturing of collagen‐based materials and limit some applications, such as electrospinning and injectable products . In electrospinning, nanofibers are obtained as a result of the electrostatic charges surpassing the surface tension of collagen molecules in concentrated AA solution.…”