Scientists create new IR-activated coating for local drug delivery

The coating is based on active substances, in particular, bone morphogenetic protein 2 (BMP-2), loaded into the titania layer and modified by polypyrrole. If this coating is fabricated on the implant surface, it is possible to accelerate the injury recovery and to control this process using infrared radiation (IR). This paper is published in Advanced Materials Interfaces.

Scientists around the world are actively working on systems for targeted delivery of drugs directly to the site of injury. This allows for effective use of lower dosages of the injected drug, reducing the impact on the liver and kidneys. The patient does not need to worry about dosages and medication schedules. Moreover, it is much easier to prevent or suppress inflammation at an early stage.

"I want to create such a coating that besides stimulating osteogenesis, would have additional functions, for example, antibacterial, or, as in our case, stimulate cell differentiation towards the formation of bone tissue," says Svetlana Ulasevich, associate professor at ITMO University's Infochemistry Scientific Center. "In our work, we propose a new hybrid thermosensitive system consisting of a polypyrrole layer, a porous surface of titanium dioxide and bone morphogenetic protein (BMP-2), which can affect the formation of bone and cartilage. First, we developed a new fast and effective approach to the modification of titanium surfaces using ultrasound and to the formation of a porous oxide coating for loading bioactive molecules. The developed functional coatings are effective for storing BMP-2 and releasing BMP-2 when exposed to IR. Moreover, the local delivery and gradual release (up to 25 days) of BMP-2 is possible for regulated cell growth. Also, the fabricated surfaces have excellent biocompatibility with MC3T3-E1 preosteoblast cells. It was proved that the released BMP-2 promotes cell differentiation towards bone formation. We also conducted several experiments with local release of the substance."

An additional advantage of the new coating is the possibility of its activation by external factors, such as infrared radiation. Thus, it is possible to control the behavior of the drug in the human body and to accelerate the onset of action, if necessary. The new hybrid stimulus-responsive system holds promise for targeted, localized, sustained release of drugs and application in the development of materials for filling bone defects.

The possibility of local in vitro release of BMP-2 protein from a new functional coating has been shown. At the site of local protein release, a greater number of MC3T3-E1 preosteoblasts were observed.

As the authors of the work emphasize, the principle described in the article can potentially be used not only as a biocompatible coating on implants, but also as a substrate for controlling the behavior of cells and simultaneously growing cells on one material, which means targeted cell differentiation and co-cultivation of cell lines.

More information:
Sviatlana Ulasevich et al. Light‐to‐Heat Photothermal Dynamic Properties of Polypyrrole‐Based Coating for Regenerative Therapy and Lab‐on‐a‐Chip Applications, Advanced Materials Interfaces (2020). DOI: 10.1002/admi.202000980

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