Preconditioning process for dermal tissue decellularization using electroporation with sonication

Decellularization to produce bioscaffolds composed of the extracellular matrix (ECM) uses enzymatic, chemical, and physical methods to remove antigens and cellular components from tissues. Effective decellularization methods depend on the characteristics of tissues, and in particular, tissues with dense, complex structure and abundant lipid content are difficult to completely decellularize. Our study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues, which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe decellularization. In this study, decellularization of human dermal tissue was done by a combination of both chemical (0.05% trypsin-EDTA, 2% SDS, 1% Triton X-100) and physical methods (electroporation, sonication). After decellularization, the content of DNA remaining in the tissue was quantitatively confirmed, and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis, respectively. Conditions of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization, and conditions for electroporation and sonication without the use of detergents, unlike the methods performed in previous studies, were established to enable the complete decellularization of the skin tissue. The combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM properties. Therefore, this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

Synovial fluid niche promoted differentiation of dental follicle mesenchymal stem cells toward chondrogenesis in rheumatoid arthritis

Objectives: In this study, we aimed to investigate the differentiation potential of dental follicle mesenchymal stem cells (MSCs) in the synovial fluid (SF) niche of early-onset or end-stage rheumatoid arthritis (RA). Patients and methods: Between May 2020 and January 2021, six patients (1 male, 5 females; mean age: 57.5±11.2 years; range, 49 to 65 years) who were diagnosed with RA with the indication of SF aspiration were included in the study. The third passage dental follicle stem cells (DFSCs) were cocultured with fresh SF samples of end-stage or early-onset RA patients in micromass culture system for 21 days. SF samples were analyzed for secreted cytokines. Chondrogenic markers (CD49e, CD49f) were analyzed in DFSCs, gene expression analysis was performed for the expressions of Col I, Col II, Aggrecan and Sox-9, and histochemical analysis was performed by staining three-dimensional pellets with anti-collagen II antibody. The neutralization assay was performed with anti-interleukin (IL)-6, anti-interferon-gamma (IFN-g), and anti-IL-1beta(b). Results: The high levels of IL-1b and IL-6 were observed in end-stage RA patients’ SF samples compared to the early-onset patients (p<0.05). The CD49e and CD49f expressions in DFSCs were significantly higher in the SF samples of end-stage RA patients (p<0.05). Also, the Col II, Sox-9 and Aggrecan messenger ribonucleic acid (mRNA) expressions increased in the DFSCs, when cultured with end-stage RA patients’ SF samples (p<0.01). Collagen-II expression in histochemical analysis of micromass pellets was higher in the DFSCs cultured with end-stage RA patients’ SF samples. The neutralization of IL-6 significantly decreased the CD49e and CD49f expressions (p<0.05). Conclusion: The high levels of IL-6 in SF niche of end-stage RA patients were found to differentiate DFSCs toward chondrogenesis. Based on these findings, DFSCs can be used as a new cell-based treatment in RA patients for the cartilage damage.

Histiocytosis in Nigerian children: A report of two variants

Histiocytoses are a rare group of proliferative disorders with very similar clinical and histological pictures. We present a case report of two variants seen in an eight-month-old female and five-month-old male in a tertiary hospital in southern Nigeria. They both presented with painless neck swellings and fever, leucocytosis, neutrophilia and lymphopenia. Initial histologic examinations of the cervical lymph nodes biopsy posed a diagnostic conundrum. However, Immuno-histochemical analysis done on both sample showed CD1a, positive S100 in keeping with Langerhans cell histiocytosis in the former. While, that of the latter showed strongly positive CD68, positive S-100 in 30% cells in keeping with Sinus histiocytosis with massive lymphadenopathy (SLMH) in the latter. Clinicians should have a high index of suspicion for histiocytosis in children presenting with generalised lymphadenopathy. Also, apart from the routine histology, immunohistochemistry analysis is recommended for all cases

“Split-Face” Evaluation of Collagen Changes Induced By Periorbital Fractional CO2 Laser Resurfacing

Background Periorbital fractional CO2 laser resurfacing has been used for facial rejuvenation purposes. However, to the best of our knowledge, no study objectively assessed periorbital neoformation and remodeling of local cutaneous collagen, in a split-face model, from skin samples obtained during upper blepharoplasty. Objectives To objectively evaluate neoformation and remodeling of local cutaneous collagen after periorbital skin fractional CO2 laser resurfacing. Methods Prospective and comparative study in which 16 female subjects presenting with dermatochalasis and periorbital rhytids were evaluated. All subjects underwent unilateral periorbital fractional CO2 laser resurfacing 30 days prior to upper blepharoplasty. Quantification of types I and III collagen from laser treated and untreated eyelid skin samples obtained during upper blepharoplasty was assessed with histochemical analysis (Picrosirius Red staining). Laser resurfacing treatment was applied to the untreated side immediately after the upper blepharoplasty. Two blinded, independent physicians evaluated clinical improvement in pretreatment, 1 and 6-month post-treatment digital images. Results Histochemical analysis showed significant higher intensity in collagen types I (treated: 158.7 ± 5.3, untreated: 139.2 ± 5.0; p&lt;0.0001) and III (treated: 105.1 ± 7.7, untreated: 104.1 ± 7.1; p&lt; 0.0001) in the samples submitted to fractional CO2 laser treatment; a greater difference was detected in collagen type I. A significant improvement in periorbital rhytidosis was observed one month after laser resurfacing (23%); a greater improvement in the periorbital region was observed 6 months after laser resurfacing and upper blepharoplasty (43.67%). Conclusions Periorbital fractional CO2 laser resurfacing demonstrated to be an effective method to improve palpebral skin, with histochemical evidence of increase in collagen types I and III.