Multispectral Raman Differentiation of Malignant Skin Neoplasms In Vitro: Search for Specific Biomarkers and Optimal Wavelengths.

Confocal scanning Raman and photoluminescence (PL) microspectroscopy is a structure-sensitive optical method that allows the non-invasive analysis of biomarkers in the skin tissue. We used it to perform in vitro diagnostics of different malignant skin neoplasms at several excitation wavelengths (532, 785 and 1064 nm). Distinct spectral differences were noticed in the Raman spectra of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), compared with healthy skin. Our analysis of Raman/PL spectra at the different excitation wavelengths enabled us to propose two novel wavelength-independent spectral criteria (intensity ratios for 1302 cm-1 and 1445 cm-1 bands, 1745 cm-1 and 1445 cm-1 bands), related to the different vibrational "fingerprints" of cell membrane lipids as biomarkers, which was confirmed by the multivariate curve resolution (MCR) technique. These criteria allowed us to differentiate healthy skin from BCC and SCC with sensitivity and specificity higher than 95%, demonstrating high clinical importance in the differential diagnostics of skin tumors.

Experimental Biointegration of a Titanium Implant in Delayed Mandibular Reconstruction.

Background: Mandibular reconstruction, after extensive resection of the mandible for the treatment of oral cancer, is a well-known procedure, however, relatively little is known about bone integration into the titanium implant after reconstruction with a temporary plastic implant. The main goal of this experimental study was to study the process of osseous integration into the titanium implant in an in vivo experiment following prior mandibular reconstruction with a temporary plastic implant. Materials and Methods: Four ewes initially underwent a partial one-sided resection of the mandible, with the formation of an approximately 3 × 1 cm defect. All of the subjects received reconstruction with an implantation of a plastic plate (3 cm). The plastic plate was removed and replaced by a titanium implant at 1, 3, 6, and 12 months, accordingly. Both plastic and titanium implants were made via 3D-printing technology and personalized modeling. A total of 6 months after titanium implantation, a histological evaluation of biointegration was performed. Results: All surgeries were uncomplicated. The integration of osseous tissue into the titanium implant was seen in all cases. Histologically, each case showed variable integration of dense fibrotic tissue with fibroblasts and non-mature bone tissue with a definitive layer of bone matrix with many osteoblasts on the periphery. The prior implantation of the plastic plate did not interfere with bone integration into the titanium implant. Conclusion: Preliminary results demonstrated that a temporary plastic implant for mandibular reconstruction does not interfere with the consequent osseous biointegration of a permanent titanium implant. This shows that temporary reconstruction is a safe solution when delayed mandibular reconstruction is required due to disease severity.