Biomaterials can be used in order to aid skin during wound healing. One such example, is using porous membranes with polymer nanoparticles. The scaffold itself is made porous in order for it to resemble the extracellular matrix (ECM) of the body. It is made of polylactic acid (PLA) which is biodegradable, and it is made porous through a thermally induced phase separation technique (TIPS). The scaffold is then functionalized with type I collagen in order to create a more biomimetic environment for cells. The image below shows both a control membrane (A) and a porous membrane (B) (scale bar=100mM).
The nanoparticles were made with polycaprolactone (PCL) which a biodegradable polyester and loaded with indomethacin (IND), an anti-inflammatory drug. The nanoparticles were dispersed into the biomaterial and due to their opposite charges, the nanoparticles remained embedded within the material. The image below shows the nanoparticles within the biomaterial.
In lecture we learned about the biodegradability of materials, as well as the use of nanoparticles for drug delivery. Biodegradability describes the ability of a material to degrade within a living organism. A material can be biodegradable if it is able to be degraded, bioeliminable if it is water soluble and excretable but not degradable, and permanent if it is neither degradable or excretable. Understanding the intended use of a biomaterial is necessary in order to evaluate the biodegradability that is needed. For example, if a material needs to remain in the body for 10 years then it may be necessary to make it permanent whereas a drug delivery material that only needs to remain in the body for a couple of months may need to biodegradable in order to avoid excess surgery to remove it from the body. Nanoparticles tend to be used as vehicles for targeted drug delivery. By using nanoparticles in order to deliver drugs, the release of the drug is able to be controlled and there is also a minimalization to the drug that is lost in circulation.
The biomaterial described in the paper is made of a biodegradable material, PLA. This decision was made because the material is meant to be used for wound healing, which indicates that it should not remain in the body for a long time. Additionally, the material is likely to cause a foreign-body reaction which will lead to inflammation at the site of implantation. In order to combat this issue, the material also contained pores so that it resembles ECM and used nanoparticles to deliver anti-inflammatory drugs. In this material, nanoparticles were used as a drug delivery vehicle because they are able to remain within the material and release the drug over time to the targeted site. Since the current “clinical gold-standard” for skin wounds is transplanting autologous tissue, this biomaterial seems to be a step in the right direction as it is design to mimic human tissue and contains drugs to prevent inflammation. However, the paper focused more on the mechanical characteristics of the material than on the actual biological aspects. Therefore, I believe that the material may be improved if more research is done on the drugs that the nanoparticles are loaded with, as well as testing to see if the changing the rate of drug release can improve the success of wound healing at the site.