Covalent Organic Frameworks as a Biomacromolecule Immobilization Platform for Biomedical and Related Applications

Abstract

With the development of biotherapeutic field, biomacromolecules with definite curative and small side effects have gradually become a hot spot in the research and development of new drugs. However, the use of biomacromolecules as drug candidates pose some technical difficulties related to their medicinal properties, mainly drug stability and in vivo transport and delivery. Currently, diverse nanodrug delivery systems have been used to deliver biomacromolecules because they can maintain stability, significantly increase bioavailability, and improve targeted distribution of biomacromolecules, thereby improving efficacy and reducing toxicity. In recent years, covalent organic frameworks (COFs) have attracted increasing interest as stable, efficient, and reusable biomacromolecule immobilization carriers. COFs exhibit good stability and biocompatibility with no biological toxicity, making them outstanding host materials for immobilizing biomacromolecules. However, the synthesis of COFs requires severe experimental conditions; the commonly used strategies for immobilizing biomacromolecules in metal-organic frameworks (MOFs), such as biomimetic mineralization, one-pot synthesis, and coprecipitation, are likely not applicable to COFs. Herein, three strategies for immobilizing biomacromolecules in COFs and the multifunctional biomedical applications of the biomacromolecule@COF composite systems are reviewed. Next, the superior properties and cutting-edge applications of MOFs are mentioned and then the advantages of COF-MOF hybrid materials are highlighted.

Delivery of Small-Molecule Drugs and Protein Drugs by Injectable Acid-Responsive Self-Assembled COF Hydrogels for Combinatorial Lung Cancer Treatment

“…COFs possess several advantageous properties such as a high specific surface area, an adjustable pore size, a diverse composition, easy surface functionalization, and high biocompatibility, which make them suitable for hosting gas molecules, biological macromolecules, and nanoparticles. − The use of COFs as carriers for protein drugs is an emerging protein immobilization technology. Protein immobilization on COFs can be achieved through surface anchoring and internal encapsulation. − Surface anchoring involves fixing proteins on the surface of COFs by physical adsorption or chemical bonding. This approach overcomes the limitations of internal encapsulation that depend on the pore size.…”

The Promise and Potential of Metal–Organic Frameworks and Covalent Organic Frameworks in Vaccine Nanotechnology

“…This strategy is more intricate and costly than one-pot synthesis, which restricts these complexes' mass production and clinical applications. 232 Recent work by Gao et al does pave the way for the future; they developed a mechanochemical strategy for de novo encapsulation of an enzyme inside the COF TpPa-1, which also stabilizes the enzyme against acid, heat, or denaturing agents. 121 Further work will still be required to develop a library of structurally diverse, highly customizable COFs with suitable chemical and morphological properties to immobilize a variety of biomacromolecules, including proteins, drugs, and antibodies.…”

Strategies for utilizing covalent organic frameworks as host materials for the integration and delivery of bioactives

“…[16][17][18] However, only a few further presented the diverse bio-applications of COFs. [19][20][21] Also, another limitation of existing reviews on COF-based carrier systems in the biomedical field is that almost all focused on cancer therapy, while ignoring other applications. 22 Thus, in this review, we highlight the importance of COFs as host materials for the delivery of bioactives and their applications, not only in cancer therapy but also in other biomedical fields.…”