Construction of Core‐Shell NanoMOFs@microgel for Aqueous Lubrication and Thermal‐Responsive Drug Release

Abstract

The construction of porous nanocarriers with good lubricating performance and stimuli‐responsive drug release is significant for the synergetic therapy of osteoarthritis (OA). Although metal‐organic framework nanoparticles (nanoMOFs) as carriers can support drug delivery, achieving the synergy of aqueous lubrication and stimuli‐responsive drug release is challenging. In this work, a core‐shell nanoMOFs@poly(N‐isopropylacrylamide) (PNIPAm) microgel hybrid via one‐pot soap‐free emulsion polymerization is developed. Programmable growth of the PNIPAm microgel layer on the surface of nanoMOFs is achieved by tuning the concentration of the monomer and the crosslinker in the reaction. Reversible swelling‐collapsing behaviors of the hybrid are realized by tuning the temperature below and above the lower critical solution temperature. When used as water lubrication additives, the hybrid enables reductions in both the coefficient of friction and wear volume. In vitro thermal‐responsive drug release is demonstrated on the diclofenac sodium‐loaded hybrid by controlling the swelling and collapsing states of the PNIPAm nanolayer. Moreover, the good biocompatibility of the hybrid is verified by culturing toward HeLa and BEAS‐2B cells. These results establish a nanoMOFs@microgel hybrid that can achieve friction and wear reduction and thermal‐responsive drug release.

Advances in metal–organic framework-based hydrogel materials: preparation, properties and applications

“…The matrix of the majority of MOF-based hydrogels is sourced from biocompatible or biological materials, which can greatly improve the application of composite materials in medical fields, such as surgical dressings and drug support. 161–171…”

Thermal-Response Proton Conduction in Schiff Base-Incorporated Metal–Organic Framework Hybrid Membranes under Low Humidity Based on the Excited-State Intramolecular Proton Transfer Mechanism

“…In many cases, temperature stimulation can be efficiently designed and manually controlled with temperature as one of the most common stimuli, which has attracted many researchers to develop advanced thermal-responsive materials in different fields, such as in reversible thermal responsive poly-acrylamide (PAAM)/poly­(acrylic acid) (PAAC)-based porous gated membranes, polycaprolactone (PCL)-based thermal phase-change materials (TPCM) with shape memory functions, and thermosensitive polyoxometalate (POM)-based memristors . Regarding MOFs, there are a few examples to build thermal-responsive MOFs, such as by introducing a thermal-responsive molecule (poly­( N -isopropyl acrylamide), PNIPAM) into UIO-66 and MIL-101, applying a controlled release of drugs and water capture/release, respectively. − In addition, some thermal-responsive MOFs have been directly prepared by grafting functional groups, such as [Cu 2 (BTR) 2 ]·2NO 3 · x G (BTR = 4,4′-bis­(1,2,4-triazole)), which has a thermal-response gated adsorption behavior, which depends on the thermal movement of NO 3– counterions on the frame, thus giving the MOF strong selection and adsorption performance for CO 2 molecules; a Cu-based MOF with a butterfly-type ligand comprising isophthalic acid (ipa) and phenothiazine-5,5-dioxide moieties (OPTz) that process the ability of temperature-induced pore size changes that allow precise control of the diffusion of gas molecules; and a 3D Sr-based MOF using tetraphenylethylene as an organic ligand, which has reversible thermosensitive fluorescence luminescence derived from the chromophore of TPE in manufacturing biological detection devices with switching properties . However, thermal-responsive MOF materials are emerging in an endless stream, but they are rarely involved in proton conduction.…”

Recent Advances in Metal–Organic-Framework-Based Nanocarriers for Controllable Drug Delivery and Release

“…have attracted more attention to construct MOFs in the application of drug delivery. Moreover, targeted drug release is an important consideration in clinical applications [47], which can be realized via different external stimulus responses such as light [48][49][50], the pH value [51][52][53], and temperature [54][55][56][57]. Compared with thermal-and light-stimulus responsibility, acid stimulation is applied more in MOF-based drug carriers for cancer treatment because of the weakly acidic environment of cancer cells and the fragile coordination bond.…”