3. Biodistribution of needle-injections and needle-free jet-injections visualized by a 3D- Fluorescent Imaging Cryomicrotome System 87 3. Despite the above-mentioned limitations, the preliminary findings of this exploratory study are important for the clinical practice. Improving knowledge of drug biodistribution in keloids is not only important to enhance efficacy and safety for TCA, but also for other intralesionally administered drugs such as 5-fluorouracil and bleomycin. This exploratory study provides a framework for future studies on drug distribution. Future research may focus on improving biodistribution in keloids, either by changing the device for injection, injection technique of the physician (e.g. level of injection, perforation technique) or mechanical tissue properties (e.g. by hyperthermia, cryotherapy, radiotherapy and lasers). Interestingly, previous research in tumors demonstrated better biodistribution of certain tumor drugs when applied with a multiside hole needle (22 holes at the side of the needle) instead of the conventional ‘end hole needle’ [8]. Other future research challenges to better understand drug biodistribution are the measurement of absolute TCA volumes, concentrations and dimensions. A quantitative technique such as ELISA could be used to measure the drug concentrations in different skin levels. In conclusion, our experiments indicate that TCA biodistribution in keloids is highly variable for both needle and jet injection. This may partly explain the variable treatment effects of intralesional TCA in keloids. Moreover, with jet injectors the fluorescent TCA volume seems to be smaller compared to needle injection in keloids. However, more experiments are needed to confirm the findings of this exploratory study.
RkJQdWJsaXNoZXIy MTk4NDMw