Therapeutic plasmapheresis (TP) is the process of the separation and removal of plasma from other blood components and is considered as an adjunctive treatment strategy to the discarded abnormal agent in the management of respiratory viral pandemics. This article reviews the mechanisms of immunopathogenesis and coagulopathy induced by SARS-CoV-2 and the potential benefits of TP as adjunctive treatment in critically COVID-19 patients.

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A novel poly­(urethane-urea) (PUU) based on poly­(glycolide-co-ε-caprolactone) macro-diol with tunable mechanical properties and biodegradation behavior is reported for corneal stromal tissue regeneration. Zn–Al layered double hydroxide (LDH) nanoparticles were synthesized and loaded with vitamin C (VC, VC-LDH) and dispersed in the PUU to control VC release in the cell culturing medium. To mimic the corneal stromal EC, scaffolds of the PUU and its nanocomposites with VC-LDH (PUU-LDH and PUU-VC-LDH) were fabricated via electrospinning. Average diameters of the aligned nanofibers were recorded as 325 ± 168, 343 ± 171, and 414 ± 275 nm for the PUU, PUU-LDH, and PUU-VC-LDH scaffolds, respectively. Results of hydrophilicity and mechanical properties measurements showed increased hydrophobicity and reduced tensile strength and elongation at break upon addition of nanoparticles to the PUU scaffold. VC release studies represented that intercalation of the drug in Zn-Al-LDH controlled the burst release and extended the release period from a few hours to 5 days. Viability and proliferation of stromal keratocyte cells on the scaffolds were investigated via AlamarBlue assay. After 24 h, the cells showed similar viability on the scaffolds and the control. After 1 week, the cells showed some degree of proliferation on the scaffolds, with the highest value recorded for PUU-VC-LDH. SEM images of the scaffolds after 24 h and 1 week confirmed good penetration and attachment of keratocytes on all the scaffolds and the cells oriented with the direction of nanofibers. After 1 week, the PUU-VC-LDH scaffold was fully covered by the cells. Immunocytochemistry assay (ICC) was performed to investigate secretion of vimentin protein, ALDH3A1, and α-SMA by the cells. After 24h and 1 week, remarkably higher levels of vimentin and ALDH3A1 and lower level of α-SMA were secreted by keratocytes on PUU-VC-LDH compared to those on the PUU and PUU-LDH scaffolds and the control. Our results suggest that the aligned PUU-VC-LDH is a promising candidate for corneal stromal tissue engineering due to the presence of zinc and vitamin C.

The aim of this work was to determine whether conjugation of cultivated choroidal melanoma and Burkitt's lymphoma cells with gold nanoparticles (GNPs) is beneficial for these series of ocular cancer patients. GNPs are radiosensitizers and can sensitize tumors to radiotherapy.This application has been examined in several tumor types, but not in choroidal melanoma. This study shows the results of in vitro study on the choroidal melanoma and also Burkitt's lymphoma cells in the presence of GNPs during continuous gamma irradiation. Cytotoxicity of GNPs were assessed for five different concentrations then cultured melanoma and Burkitt's lymphoma cells were irradiated with a Gamma source in the presence and absence of NPs. Incubation of melanoma cells with GNP concentrations below 100 μg/ml, accompanied by gamma irradiation, increased cell death (P value = 0.016) . In the absence of irradiation, GNPs at these concentrations did not affect cultured melanoma cell metabolism. Reduced cell viability resulted from a significant increase in absorbed energy by the tumor. Moreover, GNP concentrations higher than 200 μg/ml induced cytotoxicity in melanoma cells. Cytotoxicity assay in GNPs‐loaded Burkitt's lymphoma cells showed a slight decrease in cell viability at 50 μg/ml and clear cytotoxicity at concentrations higher than 100 μg/ml (P value = 0.035). Concentration and proper injection doses of GNPs in sensitive tissues such as the human eye are important variables yet to be determined.This is the first report of choroidal melanoma dosimetry performed in the presence of GNPs and provides valuable insights into future therapeutic approaches. Further in vitro study with more different sizes and concentrations is needed to determine the optimum size and concentration before any clinical research in this regard.