Bi-Functional Gold Nanorod-Protein Conjugates with Biomimetic BSA@Folic Acid Corona for Improved Tumor Targeting and Intracellular Delivery of Therapeutic Proteins in Colon Cancer 3D Spheroids

Intracellular Protein Delivery: Approaches, Challenges, and Clinical Applications

Protein biologics are powerful therapeutic agents with diverse inhibitory and enzymatic functions. However, their clinical use has been limited to extracellular applications due to their inability to cross plasma membranes. Overcoming this physiological barrier would unlock the potential of protein drugs for the treatment of many intractable diseases. In this review, we highlight progress made toward achieving cytosolic delivery of recombinant proteins. We start by first considering intracellular protein delivery as a drug modality compared to existing Food and Drug Administration-approved drug modalities. Then, we summarize strategies that have been reported to achieve protein internalization. These techniques can be broadly classified into 3 categories: physical methods, direct protein engineering, and nanocarrier-mediated delivery. Finally, we highlight existing challenges for cytosolic protein delivery and offer an outlook for future advances.

Glutathione/pH-responsive copper-based nanoplatform for amplified chemodynamic therapy through synergistic cycling regeneration of reactive oxygen species and dual glutathione depletion

The rapid scavenging of reactive oxygen species (ROS) by glutathione (GSH) and insufficient endogenous hydrogen peroxide (H2O2) in tumor cells are the major factors greatly restricting the efficacy of chemodynamic therapy (CDT). Herein, we developed a tumor microenvironment (TME)-responsive Cu-based metal-mesoporous organosilica nanoplatform integrating vitamin k3 (VK3), which could deplete GSH and specifically regenerate H2O2 for amplified CDT of cancer. Once the CuO@MON-PEG/VK3 nanoparticles entered into the tumor cells through enhanced permeability and retention (EPR) effect, the organosilicon shell and CuO core would be successively degraded upon the triggering of GSH and endo/lysosomal acidity. Subsequently, the enriched tetrasulfide bridges and released Cu2+ could consume GSH substantially, thus triggering Fenton-like reaction for CDT. Furthermore, the released VK3 could be catalyzed by the highly expressed quinone oxidoreductase-1 (NQO1) inside tumor cells to generate sufficient H2O2 through a "reversible" redox cycle, which in turn promoted Cu+-mediated Fenton-like reaction. Both in vitro and in vivo studies demonstrated that this nanoplatform could achieve synergistic CDT against tumor through synergistic cycling regeneration of ROS and dual GSH exhaustion with excellent biosafety. Our finding highlight the promising potential of CuO@MON-PEG/VK3 nanoplatform with multiple oxidative stress amplification for highly efficient tumor therapy.

Dual Responsive Magnetic Drug Delivery Nanomicelles with Tumor Targeting for Enhanced Cancer Chemo/Magnetothermal Synergistic Therapy

Introduction

Stimulus-responsive nanocarrier systems are promising in cancer treatment. They improve drug stability and facilitate controlled drug release. However, single-responsive nanocarriers still face insufficient tumor targeting and low efficacy.

Methods

In this study, we synthesized folate-modified DSPE-PEOz nanomicelles with PEG chains and loaded them with magnetic iron particles and doxorubicin (DOX). Folic acid (FA) was employed as a ligand to target cancer cells actively. The nanomicelles are biocompatible and acid-sensitive drug carriers. Magnetic field-responsive nanoparticles enable moderately controlled magnetothermal therapy of tumors regardless of tumor location. The pH/magnetic field dual-responsive nanomicelles shed their PEG layer in response to tumor tissue acidity and react to magnetic fields through magnetothermal effects.

Results

In vitro and in vivo experiments demonstrated that the nanomicelles could efficiently target cancer cells, release drugs in response to pH changes, and enhance drug uptake through magnetothermal effects.

Discussion

The dual-responsive magnetic nanomicelles are expected to enhance the anti-cancer efficacy of chemo/magnetothermal synergistic therapy.

BSA modification of bacterial surface: a promising anti-cancer therapeutic strategy

BACKGROUND

Attenuated live bacterial therapy and medical BSA materials have their own advantages in anti-cancer research, and their combination is expected to overcome some of the disadvantages of conventional anti-cancer therapeutics.

METHODS AND OBJECTIVE

Utilizing the high affinity between biotin and streptavidin, BSA modification on the surface of Escherichia coli (E. coli) was achieved. Then, the adhesion and targeting abilities of BSA modified E. coli was explored on different bladder cancer cells, and the underlying mechanism was also investigated.

RESULTS

BSA modification on the surface of E. coli enhances its ability to adhere and target cancer cells, and we speculate that these characteristics are related to the expression of SPARC in different bladder cancer cell lines.

CONCLUSION

BSA and live bacteria have their own advantages in anti-cancer research. In this study, we found that E. coli surface-modified by BSA had stronger adhesion and targeting effects on bladder cancer cells with high expression of SPARC. These findings pave the way for the future studies exploring the combination of BSA combined with live bacteria for cancer therapy.

Bi-Functionalized Transferrin@MoS2-PEG Nanosheets for Improving Cellular Uptake in HepG2 Cells

Pre-coating with a protein corona on the surface of nanomaterials (NMs) is an important strategy for reducing non-specific serum protein absorption while maintaining targeting specificity. Here, we present lipoic acid-terminated polyethylene glycol and transferrin bi-functionalized MoS₂ nanosheets (Tf@MoS₂-PEG NSs) as a feasible approach to enhance cellular uptake. Tf@MoS₂-PEG NSs can maintain good dispersion stability in cell culture medium and effectively protect MoS₂ NSs from oxidation in ambient aqueous conditions. Competitive adsorption experiments indicate that transferrin was more prone to bind MoS₂ NSs than bovine serum albumin (BSA). It is noteworthy that single HepG2 cell uptake of Tf@MoS₂-PEG presented a heterogeneous distribution pattern, and the cellular uptake amount spanned a broader range (from 0.4 fg to 2.4 fg). Comparatively, the intracellular Mo masses in HepG2 cells treated with BSA@MoS₂-PEG and MoS₂-PEG showed narrower distribution, indicating homogeneous uptake in the single HepG2 cells. Over 5% of HepG2 cells presented uptake of the Tf@MoS₂-PEG over 1.2 fg of Mo, about three-fold that of BSA@MoS₂-PEG (0.4 fg of Mo). Overall, this work suggests that Tf coating enhances the cellular uptake of MoS₂ NSs and is a promising strategy for improving the intracellular uptake efficiency of cancer cells.

Harnessing Protein Corona for Biomimetic Nanomedicine Design

Nanoparticles (NPs) are usually treated as multifunctional agents combining several therapeutical applications, like imaging and targeting delivery. However, clinical translation is still largely hindered by several factors, and the rapidly formed protein corona on the surface of NPs is one of them. The formation of protein corona is complicated and irreversible in the biological environment, and protein corona will redefine the “biological identity” of NPs, which will alter the following biological events and therapeutic efficacy. Current understanding of protein corona is still limited and incomplete, and in many cases, protein corona has adverse impacts on nanomedicine, for instance, losing targeting ability, activating the immune response, and rapid clearance. Due to the considerable role of protein corona in NPs’ biological fate, harnessing protein corona to achieve some therapeutic effects through various methods like biomimetic approaches is now treated as a promising way to meet the current challenges in nanomedicine such as poor pharmacokinetic properties, off-target effect, and immunogenicity. This review will first introduce the current understanding of protein corona and summarize the investigation process and technologies. Second, the strategies of harnessing protein corona with biomimetic approaches for nanomedicine design are reviewed. Finally, we discuss the challenges and future outlooks of biomimetic approaches to tune protein corona in nanomedicine.