Silk as an innovative biomaterial for cancer therapy

Silk has been used for centuries in the textile industry and as surgical sutures. In addition to its unique mechanical properties, silk possesses other properties, such as biocompatibility, biodegradability and ability to self-assemble, which make it an interesting material for biomedical applications. Although silk forms only fibers in nature, synthetic techniques can be used to control the processing of silk into different morphologies, such as scaffolds, films, hydrogels, microcapsules, and micro- and nanospheres. Moreover, the biotechnological production of silk proteins broadens the potential applications of silk. Synthetic silk genes have been designed. Genetic engineering enables modification of silk properties or the construction of a hybrid silk. Bioengineered hybrid silks consist of a silk sequence that self-assembles into the desired morphological structure and the sequence of a polypeptide that confers a function to the silk biomaterial. The functional domains can comprise binding sites for receptors, enzymes, drugs, metals or sugars, among others. Here, we review the current status of potential applications of silk biomaterials in the field of oncology with a focus on the generation of implantable, injectable and targeted drug delivery systems and the three-dimensional cancer models based on silk scaffolds for cancer research. However, the systems described could be applied in many biomedical fields

Oncogenic BRAF mutations and p16 expression in melanocytic nevi and melanoma in the Polish population

Introduction: Twenty-five – fifty percent of skin melanomas arise from nevi. Melanocyte proliferation is activated by BRAF V600E , then is arrested, but single nevi transform to melanomas. p16 controls arrest, and p16 loss may promote transformation. Aim : To analyze BRAF V600E , p16 expression and melanocyte proliferation in dermal, compound and dysplastic nevi, cells of primary and metastatic melanoma in the Polish population. Material and methods : One hundred and thirty-two nevi (dermal, compound, dysplastic) and 41 melanomas (in situ, primary, metastatic) were studied. BRAF was assessed by cobas® 4800 BRAFV600 Mutation Test, High Resolution Melting Assay validated with: pyrosequencing and immunohistochemistry. p16 and Ki67 expression was analyzed by IHC. Results : Eighty-two percent of nevi and 57% of melanomas display BRAF V600E expression. Most dermal and compound nevi had > 50% of p16(+) cells. BRAF V600E dysplastic nevi had a low number of p16(+) cells. Nevi without BRAF V600E (WT), had 90% of cells p16(+). In 60% of in situ and primary melanomas, there was a low number of cells of p16(+). Fifty percent of WT metastatic melanoma and 33% of BRAF V600E showed a high level of p16. The number of Ki67(+) cells in dysplastic nevi was very low. In 25% of BRAF V600E melanomas in situ and 55% of WT, > 10% cells were Ki67(+). All BRAF V600E primary melanomas and 66% of WT had > 10% Ki67(+) cells. Twenty percent of BRAF V600E and WT metastases had > 10% of Ki67(+), however, 62% of BRAF V600E and 32% of WT samples had > 50% of Ki67(+) cells. Conclusions : BRAF V600E and p16 are more frequent in nevi than in melanoma in vivo. A significantly higher p16 expression was observed in mutated nevi than in WT, while in melanoma it was just the opposite. The proliferation rate of melanoma cells negatively correlated with p16 expression