Ranpirnase (OKG-0301), a Novel Ribonuclease, Demonstrates Antiviral Activity against Adenovirus in the Ad5/NZW Rabbit Ocular Replication Model.

Adenovirus ocular infections are common ocular viral infections seen worldwide, for which there is no approved antiviral therapy available. Ranpirnase is a novel ribonuclease which preferentially degrades tRNA resulting in an inhibition of protein synthesis. The study goal was to determine the anti-adenoviral activity of topical formulations of ranpirnase (OKG-0301) on adenoviral replication in the Ad5/NZW rabbit ocular replication model. NZW rabbits were inoculated in both eyes with human adenovirus type 5 (HAdV5) after corneal scarification. A day later, topical therapy was initiated in both eyes with 0.03% OKG-0301, 0.003% OKG-0301, saline or 0.5% cidofovir. Eyes were cultured to determine HAdV5 eye titers over 2 weeks. OKG-0301 (0.03% and 0.003%) and 0.5% cidofovir decreased viral titers compared to saline. Furthermore, both OKG-0301 formulations and 0.5% cidofovir shortened the duration of the HAdV5 infection compared to saline. Both 0.03% OKG-0301 and 0.003% OKG-0301 demonstrated increased antiviral activity compared to saline in the Ad5/NZW rabbit ocular replication model. The antiviral activity of the OKG-0301 groups was similar to that of the positive antiviral control, 0.5% cidofovir. Ranpirnase (OKG-0301) may be a potential candidate for a topical antiviral for adenoviral eye infections. Further clinical development is warranted.

Comparison of three different fat graft preparation methods: gravity separation, centrifugation, and simultaneous washing with filtration in a closed system.

BACKGROUND: Successful long-term volume retention of an autologous fat graft is problematic. The presence of contaminating cells, tumescent fluid, and free lipid in the graft contributes to disparate outcomes. Better preparation methods for the fat graft before transplantation may significantly improve results. METHODS: Subcutaneous fat from 22 donors was divided and processed using various graft preparation methods: (1) no manipulation control, (2) gravity separation, (3) Coleman centrifugation, and (4) simultaneous washing with filtration using a commercially available system (Puregraft; Cytori Therapeutics, Inc., San Diego, Calif.). Fat grafts from various preparation methods were examined for free lipid, aqueous liquid, viable tissue, and blood cell content. Adipose tissue viability was determined by measuring glycerol release after agonist induction of lipolysis. RESULTS: All test graft preparation methods exhibited significantly less aqueous fluid and blood cell content compared with the control. Grafts prepared by washing with filtration exhibited significantly reduced blood cell and free lipid content, with significantly greater adipose tissue viability than other methods. CONCLUSION: Washing with filtration within a closed system produces a fat graft with higher tissue viability and lower presence of contaminants compared with grafts prepared by alternate methods.

Fresh and cryopreserved, uncultured adipose tissue-derived stem and regenerative cells ameliorate ischemia-reperfusion-induced acute kidney injury.

BACKGROUND: Acute kidney injury (AKI) represents a major clinical problem with high mortality and limited causal treatments. The use of cell therapy has been suggested as a potential modality to improve the course and outcome of AKI. METHODS: We investigated the possible renoprotection of freshly isolated, uncultured adipose tissue-derived stem and regenerative cells (ADRCs) before and after cryopreservation in a rat ischemia-reperfusion (I-R) model of AKI. RESULTS: We demonstrated that ADRC therapy drastically reduced mortality (survival 100% vs. 57%, ADRC vs. controls, respectively) and significantly reduced serum creatinine (sCr on Day 3: 3.03 ± 1.58 vs. 7.37 ± 2.32 mg/dL, ADRC vs. controls, respectively). Histological analysis further validated a significantly reduced intratubular cast formation, ameliorated acute tubular epithelial cell necrosis and mitigated macrophage infiltration. Furthermore, a reduced RNA expression of CXCL2 and IL-6 was found in the ADRC group which could explain the reduced macrophage recruitment. Use of cryopreserved ADRCs resulted in an equally high survival (90% vs. 33% in the control group) and similarly improved renal function (sCr on Day 3: 4.64 ± 2.43 vs. 7.24 ± 1.40 mg/dL in controls). CONCLUSIONS: Collectively, these results suggest a potential clinical role for ADRC therapy in patients with AKI. Importantly, cryopreservation of ADRCs could offer an autologous treatment strategy for patients who are at high risk for AKI during planned interventions.

Adipose tissue-derived cells improve cardiac function following myocardial infarction.

BACKGROUND: Adipose tissue consists of mature adipocytes and a mononuclear cell fraction termed adipose tissue-derived cells (ADCs). Within these heterogeneous ADCs exists a mesenchymal stem cell-like cell population, termed adipose tissue-derived stem cells. An important clinical advantage of adipose tissue-derived stem cells over other mesenchymal stem cell populations is the fact that they can be isolated in real time in sufficient quantity, such that ex vivo expansion is not necessary to obtain clinically relevant numbers for various therapeutic applications. MATERIALS AND METHODS: The aim of this investigation was to evaluate the therapeutic potential of freshly isolated ADCs in treating rats acutely following myocardial infarction. Rats underwent 45 min of left anterior descending artery occlusion followed by reperfusion. Fifteen minutes post-myocardial infarction, saline or 5 x 10(6) ADCs from green fluorescent protein-expressing transgenic rats were injected into the chamber of the left ventricle. Left ventricular function and morphometry was followed with 2-D echocardiography for 12 wk, at which point hearts were harvested for histological analysis. RESULTS: Twelve weeks following cell therapy, left ventricular end-diastolic dimension was less dilated while the ejection fraction and cardiac output of ADC-treated rats were significantly improved compared to control rats (P < 0.01). Despite this benefit, absolute engraftment rates were low. This paradox may be partially explained by ADC-induced increases in both capillary and arteriole densities. CONCLUSIONS: These data confirm the therapeutic benefit of freshly isolated ADCs delivered post-MI and suggest a novel beneficial mechanism for ADCs through a potent proangiogenic effect.

Adipose-derived cells.

Heart failure is by far the most common cause of hospitalization in Western countries, with onerous economic consequences. Cell therapy holds great promise for use in tissue regeneration and is increasingly used in an effort to improve outcomes in cardiac disease. Recently it has been shown that adipose tissue, in addition to committed adipogenic, endothelial progenitor cells and pluripotent vascular progenitor cells, also contains multipotent cell types (adipose-derived stem cells, ADSCs) that, in cell culture conditions, have shown to have an impressive developmental plasticity including the ability to undergo multilineage differentiation and self-renewal. ADSCs express multiple CD marker antigens similar to those observed on MSCs and are also capable of secreting a large number of angiogenesis-related cytokines, including vascular endothelial growth factor, granulocyte/macrophage colony stimulating factor, stromal-derived factor-1alpha, and hepatocyte growth factor. Adipose tissue can be harvested in large quantities with minimal morbidity in several regions of the body and, on average, 100 ml of human adipose tissue yields about 1 x 10(6) stem cells. Studies conducted in porcine AMI models have shown a significant LV functional improvement, with no report of any potentially fatal arrhythmias. The APOLLO trial, a prospective, double blind, randomized, placebo-controlled trial currently in the recruiting phase, is a "first-in-man" study that explores the safety and feasibility of ADSC transplantation in patients with acute MI.

Multipotential differentiation of adipose tissue-derived stem cells.

Tissue engineering offers considerable promise in the repair or replacement of diseased and/or damaged tissues. The cellular component of this regenerative approach will play a key role in bringing these tissue engineered constructs from the laboratory bench to the clinical bedside. However, the ideal source of cells still remains unclear and may differ depending upon the application. Current research for many applications is focused on the use of adult stem cells. The properties of adult stem cells that make them well-suited for regenerative medicine are (1) ease of harvest for autologous transplantation, (2) high proliferation rates for ex vivo expansion and (3) multilineage differentiation capacity. This review will highlight the use of adipose tissue as a reservoir of adult stem cells and draw conclusions based upon comparisons with bone marrow stromal cells.

The growing importance of fat in regenerative medicine.

A recent publication by Michael Longaker and colleagues represents a landmark for the use of adipose tissue as a source of cells for tissue regeneration. The authors investigated the ability of adipose tissue-derived cells (ADCs) to regenerate critical size calvarial (superior portion of the skull) defects in mice by using a novel osteoconducive apatite-coated Poly-lactic-co-glycolic acid (PLGA) scaffold for cell delivery. Direct comparison of this osteogenic ability was performed with bone marrow stromal cells and juvenile calvarial-derived osteoblasts.