In immunology, histocompatibility refers to the genetic mechanism that predicts tissue and organ transplant rejection based on immunological recognition of histocompatibility antigens. The term also refers to the research of the factors that influence whether transplanted tissues or organs are accepted or rejected. The higher the histocompatibility, the lesser the immunological response; in some cases, no immune response occurs.
Surface modification for histocompatibility research has recently concentrated on cell transplantation and medical implants to combat graft rejection. Surface modification techniques have been employed to control thrombosis, bacterial infection, and inflammation through local drug release or comparable biological processes, avoiding systemic administration. Alfa Chemistry has conducted substantial study on how to change the surface of biomaterials to modulate their histocompatibility.
Histocompatibility Surface Strategies
After implantation of biomaterials in the body, the host response includes a variety of processes generally described as blood-matter interactions, temporary matrix formation, inflammation, granulation tissue development, foreign body reaction, and fibrous envelope development. The composition and severity of the reactions are determined by the surface chemistry, morphology, and morphology of the biomaterial.
Alfa Chemistry has specifically investigated the ability of chemical surface modification of biomaterials to achieve histocompatibility, which may be a new hotspot in the future. Our research and application of chemical surface modification of biomaterials are extensive and fruitful. If you would like to quickly modify the surface of your product for biomedical applications, please contact us.
Biomimetic superhydrophilic and superhydrophobic coatings, zwitterionic polymer grafting, polyethylene glycol coatings, antibiotic-loaded coatings, and heparin-loaded coatings are among the most often employed surface modification techniques for blood-contacting materials. There are still some issues with these well-studied coating technologies, such as the time-consuming and complicated preparation process and medication activity interference. Furthermore, few coatings exhibit anti-inflammatory characteristics, which is an important consideration for blood contact materials.
Inflammation can stimulate thrombosis. In addition, bacterial infections and foreign substances can induce inflammation in varying degrees. Alfa Chemistry's goal is to create a simple, effective, and long-lasting surface modification technology that not only fits the antibacterial and anticoagulant needs of blood contact materials but also has great anti-inflammatory qualities.
Fig 1. Pharmacological description of HK (a-c) and HK-modified coating (d) structures. (Li L, et al. 2021)
Honokiol (HK) is a physiologically active natural substance having a wide range of biological functions, including antioxidant, anti-inflammatory, and antibacterial properties. Alfa Chemistry's surface modification technology allows the efficient introduction of drugs to the surface of materials without destroying their activity. By covalently grafting HK onto the surface of blood contact materials, we were able to create DPHc coatings. To generate an amine-rich surface for immobilization of aldehyde-modified HK, PEI was co-deposited with modest quantities of dopamine.
S. aureus and E. coli were resistant to the DPHc coating for an extended period of time. In macrophages, the DPHc coating drastically reduced inflammatory factor activation, proliferation, and secretion. Meanwhile, a subcutaneous embedding test in SD rats revealed that the organisms had just a little foreign body reaction to the DPHc coating, showing that the DPHc coating is highly histocompatible. This multifunctional DPHc coating can not only prevent thrombosis and infection but can also reduce the irritation caused by blood contact materials, allowing HK to be used in more biomaterials.
Reference
- Li L, et al. (2021). "A Honokiol-Mediated Robust Coating for Blood-Contacting Devices with Anti-Inflammatory, Antibacterial and Antithrombotic Properties." J. Mater. Chem. B. 9: 9770-9783.
