Study of Human Amniotic Membrane Mesenchymal Stem Cells Using Gelatin and Alginate as Nontoxic Scaffolds

Perinatal mesenchymal stem cells (MSCs), for example, from amniotic membrane, have advantages over adult sources, such as bone marrow, in terms of ease of availability, cell naivety, tissue stem cell abundance, high capacity of proliferation, and less donor site morbidity, because it does not require invasive procedures. Natural polymer scaffolds, such as gelatin and alginate, are biocompatible. Combination of stem cells from amniotic membrane (hAMSCs) and gelatin or alginate as scaffold can be promising. However, cytotoxicity comparison of gelatin and alginate to hAMSCs has not been widely studied. This study was aimed to compare cytotoxicity of gelatin and alginate on hAMSCs in vitro. Isolation and culture were performed on hAMSCs of the healthy full-term pregnancy. In passage 4, Flow Cytometry CD90, CD105, and CD73 phenotype characterization was done. Colorimetric assay of 3-(4,5-dimethythiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) was performed to measure the cytotoxicity. There were three sample groups: (control group) hAMSCs with alpha-minimum essential medium (α-MEM) solution as control; (gelatin group) hAMSCs with gelatin; (alginate group) hAMSCs with alginate. Each group consisted of 12 samples. Flow cytometry of hAMSCs expressed 28.78% CD90, 36.95% CD105, and 44.41% CD73 surface markers. No sample depicted toxicity in either gelatin or alginate group, and this is indicated by the average percentage of living cells in gelatin 97.26% and in alginate 98.43%. No statistically significant difference (p=0.057) of cytotoxicity was found between gelatin and alginate to hAMSCs. Gelatin and alginate were nontoxic to hAMSCs in vitro

A phase 1 dose-finding and pharmacodynamic study of rapamycin in combination with bevacizumab in patients with unresectable hepatocellular carcinoma

Background & Aims Preclinical studies have demonstrated the additive effect of rapamycin with bevacizumab for hepatocellular carcinoma treatment. We conducted a Phase 1 study to evaluate the safety and pharmacokinetics of the combination in patients with hepatocellular carcinoma. Methods Adult participants with advanced hepatocellular carcinoma received intravenous bevacizumab (5mg/kg every 14days) and oral rapamycin (1–6mg/day; 3+3 dose escalation design). Computed tomography assessed tumour response and treatment safety. Pharmacokinetics assessment established rapamycin blood concentrations pre- and post-dose. Dynamic contrast-enhanced computed tomography analysed the tumour region for blood flow, permeability surface area product, fractional intravascular blood volume and extracellular–extravascular volume. Results Twenty-four participants were treated. There were two dose limiting toxicities with rapamycin 5mg: grade 3 thrombocytopenia and grade 3 mucositis. The maximally tolerated dose of rapamycin was 4mg. Adverse events (grade 1–2) included hyperglycaemia (83%), thrombocytopenia (75%), fatigue (46%), mucositis (46%), anorexia (42%), diarrhoea (33%) and proteinuria (12.5%). Of 20 evaluable participants, one reached complete response that lasted 4.5months, two reached partial response, 14 reached stable disease and three had progressive disease. Median overall survival was 9.4months; progression-free survival was 5.5months. Dose level and steady state area under the concentration time curve for hour zero to infinity of rapamycin correlated inversely with blood flow rate and change in permeability-surface area. After 22days of treatment, there were significant reductions from baseline in blood flow rate, permeability-surface area and fractional intracellular blood volume. Conclusions The recommended Phase 2 dose of rapamycin is 4mg in combination with bevacizumab. Evidence of anti-vascular activity was observed together with promising clinical activity