Nanocarrier-mediated protein delivery is a promising strategy for fundamental research and therapeutic applications. However, the efficacy of the current platforms for delivery into cells is limited by endosomal entrapment of delivered protein cargo with concomitantly inefficient access to the cytosol and other organelles, including the nucleus. We report here a robust, versatile polymeric–protein nanocomposite (PPNC) platform capable of efficient (≥90%) delivery of proteins to the cytosol. We synthesized a library of guanidinium-functionalized poly­(oxanorborneneimide) (PONI) homopolymers with varying molecular weights to stabilize and deliver engineered proteins featuring terminal oligoglutamate “E-tags”. The polymers were screened for cytosolic delivery efficiency using imaging flow cytometry with cytosolic delivery validated using confocal microscopy and activity of the delivered proteins demonstrated through functional assays. These studies indicate that the PPNC platform provides highly effective and tunable cytosolic delivery over a wide range of formulations, making them robust agents for therapeutic protein delivery.

Bioorthogonal activation of prodrugs provides a strategy for on-demand on-site production of therapeutics. Intracellular activation provides a strategy to localize therapeutics, potentially minimizing off-target effects. To this end, nanoparticles embedded with transition metal catalysts (nanozymes) were engineered to generate either “hard” irreversible or “soft” reversible coronas in serum. The hard corona induced nanozyme aggregation, effectively inhibiting nanozyme activity, whereas only modest loss of activity was observed with the nonaggregating soft corona nanozymes. In both cases complete activity was restored by treatment with proteases. Intracellular activity mirrored this reactivation: endogenous proteases in the endosome provided intracellular activation of both nanozymes. The role of intracellular proteases in nanozyme reactivation was verified through treatment of the cells with protease inhibitors, which prevented reactivation. This study demonstrates the use of intracellular proteolysis as a strategy for localization of therapeutic generation to within cells.

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This paper describes the fabrication of thermoresponsive bio-orthogonal catalytic systems though the integration of transition metal catalysts into gold nanoparticles. The confined assemblies of the catalysts provide a temperatureregulated system able to controllably activate antibiotics within biofilms. This work presents a blueprint for synthesizing a family of reversible thermoresponsive nanozymes with tailored activation temperatures and preserved bio-orthogonal activity in complex biological environments.

Nanomaterials encapsulate bioorthogonal catalysts enabling their application in biological environment for sustained production of functional molecules.

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Titanium is widely utilized for manufacturing medical implants due to its inherent mechanical strength and biocompatibility. Recent studies have focused on developing coatings to impart unique properties to Ti implants, such as antimicrobial behavior, enhanced cell adhesion, and osteointegration. Ca- and Si-based ceramic (CS) coatings can enhance bone integration through the release of Ca and Si ions. However, high degradation rates of CS ceramics create a basic environment that reduces cell viability. Polymeric or protein-based coatings may be employed to modulate CS degradation. However, it is challenging to ensure coating stability over extended periods of time without compromising biocompatibility. In this study, we employed a fluorous-cured collagen shell as a drug-loadable scaffold around CS nanorod coatings on Ti implants. Fluorous-cured collagen coatings have enhanced mechanical and enzymatic stability and are able to regulate the release of Ca and Si ions. Furthermore, the collagen scaffold was loaded with antimicrobial peptides to impart antimicrobial activity while promoting cell adhesion. These multifunctional collagen coatings simultaneously regulate the degradation of CS ceramics and enhance antimicrobial activity, while maintaining biocompatibility.

Collagen I (Col-I) is widely used in the fabrication of biomaterials due to its biocompatibility; however, Col-I based biomaterials are susceptible to mechanical failure during handling, which limits their applicability to biomaterials. Chemical or physical treatment can improve the mechanical properties of collagen; however, these processes can create issues of cytotoxicity or denaturation. We report here an alternative strategy to improve the stability and mechanical properties of Col-I while preserving its native structure, through thermal treatment in fluorous media. Thermal treatment of Col-I in fluorous solvent generates compact, stable films with significantly increased mechanical strength. Furthermore, the use of fluorous media significantly reduces the extent of swelling and the rate of proteolytic degradation, but it preserves the high cell biocompatibility.