Drug Delivery

Cell membrane-coated drug delivery exploits a novel top-down approach to faithfully transferring the entire cell exterior, including both lipids and membrane-associated proteins, onto synthetic nanoparticle drugs. This new class of biomimetic nanoparticle drugs has shown significant therapeutic potentials. Committed to the application of cell surface engineering in drug delivery for years, Creative Biolabs is experienced and professional in providing high-quality cell surface conjugation services to global customers.

Introduction

How to design a drug carrier that can specifically deliver drugs to the site of disease is always the main focus of current pharmaceutical research. Thanks to recent advances in material science and nanotechnology, many nanoformulations, such as liposomes, micelles, and nanoparticles, have been developed and some of them have been used in the clinic or approaching the clinical translation. Cell membrane-coated nanoparticles have unleashed the promising potential of exploiting natural functionalities of the source cells for effective drug targeting. While this class of biomimetic nanoparticles was developed not long ago, it has already demonstrated the capability of pushing the envelope of targeted nanoparticle drug delivery.

Fig.1 Schematic representation of nanoparticle surface functionalization through cell membrane coating. (Gao, 2015)

Methods and Applications

• Cell membrane coating to prolong nanoparticle circulation

For systemic drug delivery, nanoparticles with a longer circulation lifetime promise better targeting to tissues through both passive and active mechanisms. To prolong circulation, appropriate surface coatings are essential to prevent nanoparticles from early uptake by the reticuloendothelial system, including liver, spleen, bone marrow, and lymph nodes, shortly after intravenous injection. Nature has provided a plethora of long-circulating carriers. In particular, red blood cells (RBCs) have inspired the design and development of many man-made delivery systems. The unique physicochemical characteristics and biological functions of RBCs, particularly, those that enable the cells to pass through narrow constrictions while maintaining a long in vivo survival, have been mimicked and integrated into the design and engineering of drug carriers, which were expected to improve drug tolerability, circulation lifetime and therapeutic efficacy.

• Cell membrane coating to achieve cell-specific targeting

In applying nanoparticles for disease treatments, cell-specific targeting is a desirable feature that promises to minimize off-target side effects. While the majority of cell-specific targeting is accomplished through conjugation of known ligands, cell membrane-coated nanoparticles provide an opportunity to use the inherent homotypic or heterotypic adhesion properties of the source cells for drug targeting, a strategy that bypasses the laborious selection and use of extrinsic targeting ligands. Intrinsic cell adhesion properties play significant roles in biology. For example, many cancer cells express surface antigens with homophilic adhesion domains such as carcinoembryonic antigen and galectin-3 for multicellular aggregate formation in tumors. Heterotypic adhesion to the microvascular endothelium and subsequent homotypic aggregation are critical steps during hematogenous cancer metastasis.

• Cell membrane coating for immune system targeting

Cell membrane-coated nanoparticles carry an antigenic exterior closely mimicking that of the source cells, making them excellent antigen-presenting platforms for vaccine applications. One such example is the use of cancer cell membrane-coated nanoparticles (CCNPs) to promote anticancer immune responses. Relevant research has demonstrated successful induction of antigen-specific anti-cancer response through CCNPs. Cell membrane-coated nanoparticles not only replicate the antigenic exterior of the source cells but also provide tunable physicochemical properties through the synthetic cores. With such combined advantages, they confer tremendous engineering flexibility for targeting the immune system. One example was the bacterial membrane-coated gold nanoparticles (BM-AuNPs), recently developed to target lymph nodes for modulating antibacterial immunity.

Fig.2 A schematic illustration of modulating antibacterial immunity via bacterial membrane-coated nanoparticles. (Gao and Zhang, 2015)

In addition to presenting native membrane antigens, cell membrane-coated nanoparticles can also carry and deliver foreign antigens such as bacterial toxins to the immune system as toxoid vaccines, which are inactivated forms of toxins that can be administered to mount an anti-toxin immune response.

Services at Creative Biolabs

As a professional cell surface engineering services provider, Creative Biolabs has established a comprehensive technology platform. The scope of our services covers cell-nucleic acids conjugate (e.g. DNA-protein conjugate, lipid-DNA conjugate), cell-covalent conjugation (e.g. cell surface-based chemical conjugation, cell surface-based metabolic conjugation), cell-noncovalent physical bioconjugation (e.g. cell surface-based biotinylation modification, cell surface-based electrostatic interaction modification).

With years of experience focusing on cell surface engineering, Creative Biolabs will be your best partner. If you are interested in cell our services, please feel free to contact us for more information.

Reference

1. Gao, W.; Zhang, L. Coating nanoparticles with cell membranes for targeted drug delivery. J Drug Target. 2015, 23(7-8): 619-26.