Intrafibrillar mineralization plays an important role in dentin repair. Current research on intrafibrillar mineralization primarily focuses on the precise positioning of mineral precursors within collagen and the reduction of mineralization time. Inspired by the multifunctionality of noncollagenous proteins (NCPs), we developed a dual-analogue system, 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) followed by 3-(3,4-dihydroxyphenyl)-l-alanine (l-DOPA)-stabilized amorphous calcium phosphate (M + LA), which integrated a nucleation inhibitor l-DOPA and inducer 10-MDP. In this study, we investigated the impact of a preinfiltration strategy using the M + LA system on intrafibrillar mineralization. l-DOPA with a concentration of 250 μg mL–1, acting as a mussel-inspired nucleation inhibitor, was demonstrated to stabilize amorphous calcium phosphate (ACP) precursors within 2 h at 37 °C, with the formed precursors termed “LACP” (l-DOPA-stabilized amorphous calcium phosphate). Numerous LACP precursors were immobilized within collagen via the M + LA system, referred to as “preinfiltration.” The M + LA system exhibited no significant cytotoxicity, as evidenced by the biocompatibility evaluation through a modified trans-dentin disk model. Notably, the M + LA preinfiltration strategy significantly reduced intrafibrillar mineralization time to 3 h, superior to that of bare collagen and MDP-modified collagen. Furthermore, the resulting mineralized M + LA-modified collagen achieved functional mechanical properties. Moreover, 10-MDP-Ca nanolayering was generated via a bottom-up approach during the preinfiltration process. This study introduces a preinfiltration strategy for promoting intrafibrillar mineralization, which provides a reference for understanding the mechanism of intrafibrillar mineralization and shows promising clinical application prospects for dentin repair.
Tong Xu,Xiaopei Ding,Chengcai Li,Haoyang Cheng,Guojin Liu,Hailin Zhu,Yuhai Guo,Xueliang Jiang,Jiuming Li
Accelerated industrial expansion has led to significant wastewater pollution, with effluent containing the toxic heavy metal Cr(VI) posing severe threats to ecosystems and human health. The combination of metal-organic frameworks (MOFs) and membrane separation techniques offers promising solutions for pollutant removal. This study developed a polytetrafluoroethylene (PTFE)-based composite membrane for effective Cr(VI) removal from aqueous solutions. This membrane was prepared through the in-situ synthesis of zinc-zirconium bimetallic MOFs on a PTFE membrane that had been modified with L-DOPA/PEI. The composite membrane demonstrated optimal Cr(VI) adsorption at a Zr:Zn molar ratio of 1:4, under conditions of 45 °C and pH = 2, with a maximum adsorption capacity of 335.1 mg/g. The adsorption process of Cr(VI) onto the composite membrane adhered to both the pseudo-second-order kinetic model and the Freundlich adsorption isotherm. Thermodynamic analyses confirmed a spontaneous, endothermic process. The composite membrane, with its excellent adsorption capacity, filtration performance, and recyclability, stands out as a highly effective material for the removal of Cr(VI) from aqueous solutions. Furthermore, it addresses the issues of aggregation, difficulty in separation, and the recycling challenges associated with powder-like MOFs, demonstrating significant potential for practical applications.
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