关键词: 功能材料, 铜基金属有机框架材料, 肝素功能化, 静电纺丝, 肌酐, 吸附, 血液净化

Abstract:

Objective In order to develop highly efficient and safe blood purification materials for addressing the challenge of removing uremic toxins such as creatinine. This study aims to overcome the limitations of powder adsorbents and enhance creatinine clearance by functionalizing copper-based metal-organic frameworks (CuMOFs) with heparin and processing them into practical nanofiber membranes via electrospinning technology.

Methods Heparin was covalently grafted onto the surface of copper-based metal-organic frameworks (CuMOFs) by 3-aminopropyltriethoxysilane (APTES)-mediated bridging and amidation reactions, yielding heparin-functionalized materials (CuMOFs-Hep). The successful synthesis and functionalization were verified by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and Zeta potential analysis. Subsequently, CuMOFs-Hep powder was incorporated into a polyvinyl alcohol (PVA) matrix to prepare composite nanofiber membranes (CuMOFs-Hep/PVA) by electrospinning. The material's creatinine adsorption capacity was evaluated using adsorption isotherm experiments, while its biosafety was assessed by measuring copper ion (Cu²⁺) leaching and platelet adhesion behavior.

Results Comprehensive characterization confirmed the successful synthesis of CuMOFs and their heparin functionalization. Heparin modification significantly increased the surface negative charge, with a Zeta potential reaching -30.1 mV. Adsorption isotherm studies revealed that CuMOFs-Hep exhibits a theoretical maximum adsorption capacity of 267.8 mg/g for creatinine, representing a 68.7% increase compared to the pristine CuMOFs (158.7 mg/g). The CuMOFs-Hp/PVA composite fiber membrane retained a high adsorption capacity of 233.5 mg/g (87.2% of the powder adsorption capacity) while exhibiting excellent processability, forming a continuous, operable membrane morphology. The adsorption capacity of pure PVA membranes is negligible (approximately 9.1 mg/g), confirming that the high adsorption capacity of the composite membranes originates from the incorporated CuMOFs-Hep. Biosafety assessment revealed that heparin functionalization significantly reduced Cu²⁺ leaching by 89.9% (from 2.132 mg/L to 0.214 mg/L after 24 h) and markedly decreased platelet adhesion and activation on the material surface compared to unmodified CuMOFs. The electrospun nanofiber structure provides high specific surface area and a porous network, facilitating mass transfer processes and accessibility to active sites.

Conclusion This study successfully developed a high-performance creatinine adsorbent by combining heparin functionalization of CuMOFs with electrospinning textile processing technology. The resulting CuMOFs-Hep/PVA composite nanofiber membrane exhibits high adsorption capacity, excellent processability, and improved biosafety (including reduced metal ion leaching and enhanced blood compatibility). The material's efficient adsorption performance stems from the synergistic effects of strong electrostatic interactions and hydrogen bonding provided by the heparinized surface. By integrating material functionalization with electrospinning technology, this study successfully produced a composite fiber membrane with high adsorption capacity, processability, and superior biocompatibility, offering a novel strategy for developing high-performance blood purification materials.

Key words: functional material, copper-based metal-organic framework material, heparin functionalization, electrospinning, creatinine, adsorption, blood purification