Metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), invented by Yaghi, stand now a mature emerging class of crystalline porous materials, which have become important contestants in consumer and industrial applications in modern society. Their structural diversity, functional diversity, chemical stability, biocompatibility and ability to be tailored into different crystallite sizes (ranging from bulk micrometric materials down to the nanometer size) pave the way for their application in many fields, showing great application potential in the biomedical fields. Besides application of the biomedical field of drug storage and delivery, biomedical imaging and phototherapy, MOFs and COFs can also be applied in other biologically related fields like antibacterial, enzymes immobilization, protective coatings of protein, etc.
Applications of MOFs in Other Biomedical Fields
- Antibacterial: Porous MOFs can incorporate antibacterial species in their pore or even themselves can be acted as an effective antibacterial agent (through a judicious choice of the organic linkers and metal centers) in killing different types of bacteria, such as Staphylococcus aureus, S. aureus (MRSA), Escherichia coli strain, Pseudomonas aeruginosa, Saccharomyces cerevisiae, Geotrichum candidum, Bacillus subtilis and many others.
- Protective coatings: Molecular biomarkers (e.g., proteins) belonging to biological specimens (e.g., blood and urine) are less stable in general. In this sense, there is an urgent need to protect relevant biological samples for facilitating long time transportation. MOFs with pores large have emerged as potential candidate materials to address this problem, which can encapsulate and immobilize proteins, thereby enhancing their stability for future analysis. In addition, in situ MOFs synthesis can also be used to encapsulate larger biological entities, such as viruses and cells. For example, tobacco Mosaic virus (TMV) can be well encapsulated in ZIF-8.
Applications of COFs in Other Biomedical Fields
- Antibacterial: COFs with effective photosensitivity can be used as photosensitizer for photodynamic inactivation of bacteria. Taking Porphyrin-based COFs as an example, whose photostability and photosensitizing nature can generate singlet oxygen via visible light irradiation and show excellent antibacterial activity for use as an antibacterial agents and antibacterial coating. P. aeruginosa, E. faecalis, Escherichia coli, Staphylococcus aureus and many bacterias can be completely removed and destroyed by COFs.
- Enzyme stabilization: Immobilization of enzymes can improve the stability of enzymes, which plays an important place in biochemical reactions such as drug metabolism, biosensing, and biocatalysis. Common materials like mesoporous silica, magnetic nanoparticles, zeolites for enzymes immobilization suffer some drawbacks of poor stability, deficiency in functionality, and low enzyme loading. COFs can be a good candidate for the enzymes immobilization materials because of the adjustable characteristic of surface, well-defined structure, chemical and thermal stability, and undamaged morphology after loading enzymes. For instance, Banerjee and co-workers designed hollow spherical COFs (COF-DhaTab) for trypsin immobilization, various methods were used to demonstrate the immobilization of trypsin into the COFs and the loading capacity was as high as 15.5 µmol/g (as shown in Fig.1 ).
Fig.1 (a) Schematic representation of trypsin immobilization; (b) Amount of trypsin loading in COF-DhaTab; Evidence of trypsin immobilization through (c) PXRD patterns; (d) N2 adsorption isotherms; (e) TEM images; and (f) Confocal Z stacks
What Can Alfa Chemistry Do
MOFs and COFs produced by Alfa Chemistry can be well used in biomedical fields such as antibacterial, enzymes immobilization, protective coatings of protein and so on. Alfa Chemistry also provides customers with professional MOFs and COFs design and customization services, in which our professional technology team has profound research experience in the biomedical fields. No matter what design ideas you have, we will implement them together with you. Please contact us immediately to order or cooperate in research and development with high quality and reasonable price.
- Mendes R.F.; et al. Metal-organic frameworks: a future toolbox for biomedicine?[J]. Chemical Society Reviews, 2020, 49, 9121-9153.
- Kandambeth S.; et al. Self-templated chemically stable hollow spherical covalent organic framework[J]. Nature Communications, 2015, 6, 6786.