Giulia Falabella

Prolongation of skin allograft survival in rats by the transplantation of microencapsulated xenogeneic neonatal porcine Sertoli cells.

Skin rejection remains a major hurdle in skin reconstructive transplantation surgery. In fact, 85% of the grafted patients experience at least one episode of acute skin rejection in the first year. It has been observed that Sertoli cells (SC), when co-transplanted with allo- or xenogeneic cell/tissues, can induce graft acceptance in the absence of systemic immunosuppression. A method aimed at significantly prolonging skin allografts in rats transplanted with barium alginate-based microencapsulated xenogeneic porcine SC (SC-MCs) is described. Results demonstrated that intraperitoneal (IP) transplantation of SC-MCs with high cellular viability and function can significantly prolong allogeneic skin grafts when compared to transplantation controls receiving only empty alginate capsules (E-MCs). Lymphocytic infiltration at the skin graft site was not observed in 80% of the SC-MCs transplanted rats and these recipient animals showed a significant increased expression of T regulatory (Tregs) cells when compared to E-MCs transplantation controls. The findings of this report further substantiate the positive therapeutic effects of SC on transplantation technology mediated by Sertoli cell-induced alterations of the hosts immune system and indicate new perspectives and new strategies for successful skin tissue allografts.

Reversal of experimental Laron Syndrome by xenotransplantation of microencapsulated porcine Sertoli cells.

Recombinant human IGF-1 currently represents the only available treatment option for the Laron Syndrome, a rare human disorder caused by defects in the gene encoding growth hormone receptor, resulting in irreversibly retarded growth. Unfortunately, this treatment therapy, poorly impacts longitudinal growth (13% in females and 19% in males), while burdening the patients with severe side effects, including hypoglycemia, in association with the unfair chore of taking multiple daily injections that cause local intense pain. In this study, we have demonstrated that a single intraperitoneal graft of microencapsulated pig Sertoli cells, producing pig insulin-like growth factor-1, successfully promoted significant proportional growth in the Laron mouse, a unique animal model of the human Laron Syndrome. These findings indicate a novel, simply, safe and successful method for the cell therapy-based cure of the Laron Syndrome, potentially applicable to humans.

Long-term stability, functional competence, and safety of microencapsulated specific pathogen-free neonatal porcine Sertoli cells: a potential product for cell transplant therapy

Porcine Sertoli cells (pSCs) have been employed for cell therapy in pre‐clinical studies for several chronic/immune diseases as they deliver molecules associated with trophic and anti‐inflammatory effects. To be employed for human xenografts, pSCs products need to comply with safety and stability. To fulfill such requirements, we employed a microencapsulation technology to increase pre‐transplant storage stability of specific pathogen‐free pSCs (SPF‐pSCs) and evaluated the in vivo long‐term viability and safety of grafts.

Xenograft of Microencapsulated Sertoli Cells Reverses T1DM in NOD Mice by Inducing Neogenesis of Beta-Cells

Background. Sertoli cells (SCs) provide an immunoprotective environment to pancreatic islet grafts for treatment of insulin-dependent diabetes. Aim of this work was to verify whether intraperitoneal graft of SCs, enveloped in barium alginate-based microcapsules, would reverse overt spontaneous diabetes in nonobese diabetic (NOD) mice by eliciting generation of newly formed functional islets &bgr;-cells. Methods. Microcapsules were prepared, according to our method, by a mono air-jet device system and thereafter examined as far as (a) SC morphology by light microscopy; (b) SC viability by fluorescence microscopy; (c) SC in vitro function; and (d) SC in vivo function, as quoted by diabetes reversal in the NOD mice, were concerned. Results. SCs containing microcapsules exhibited excellent morphology, viability, and function, and when grafted into the NODs, they induced stable reversion of the disease in 81% of the cases. The treated mice showed dramatic increase in regulatory T lymphocytes (Treg) when compared with control diabetic NODs treated with empty capsules only. Histologic examination of pancreata retrieved from the SC-transplanted animals showed total disappearance of insulitis, with appearance of new islets, as shown by immunocytochemistry; restored ability of the islets to produce insulin, glucagon, and somatostatin; and finally, increased expression of key transcriptional factors such as neurogenin 3. Conclusions. SCs, enveloped in barium alginate-based microcapsules, showed no long-term loss of their functional and morphological properties in vitro or in vivo. Xenograft of microencapsulated-SC–induced reversal of spontaneous diabetes in the majority of the treated NOD mice, based on SC-related powerful immunomodulatory and pro-&bgr;-cell regeneration properties.

In vitro cadmium effects on ECM gene expression in human bronchial epithelial cells.

Occupational and environmental exposure to the heavy metal cadmium (Cd) and its inhalation from cigarette smoke are associated with emphysema. Many growth factors and extracellular matrix (ECM) cell signaling molecules are directly involved in the epithelial bronchial cell pathway. This study investigated the direct effects of Cd on the production of several ECM components in human bronchial epithelial cells (BEAS-2B) that were exposed in vitro for 48 h to sub-toxic and toxic concentrations of Cd. Gene expression of collagens, metalloproteases (MMPs), integrins, tenascin and vitronectin were quantified by RT-PCR. To study apoptosis cascade, annexin assay and cellular cytotoxicity by MTT assay were performed. We also investigated whether an imbalance in the TGFβ/TGFβ receptor (TGFβR) expression mediated Cd effects. The results showed the sub-toxic Cd dose significantly increased tenascin, vitronectin, β1 and β5 integrin gene expression. The toxic Cd dose decreased type IV and V collagen, α1, α2 and β3 integrins. Both Cd doses down-regulated type I collagen and up-regulated metalloproteases. Each Cd dose caused a different imbalance in the complex pattern of TGFβ and its receptors. No alteration in classic apoptotic marker protein expression was observed in presence of the sub-toxic dose of Cd, suggesting this metal alters ECM production without apoptotic activation. In conclusion, all these data show even sub-toxic Cd dose exposure alters the specific gene expression of several ECM components that are crucially implicated in the mechanical properties of lung parenchyma supporting the hypothesis that the mechanism underlying Cd-induced lung disease may involve downstream changes in TGFβ/TGFβR signaling.

Intraperitoneal injection of microencapsulated Sertoli cells restores muscle morphology and performance in dystrophic mice.

Duchenne muscular dystrophy (DMD) is a genetic disease characterized by progressive muscle degeneration leading to impaired locomotion, respiratory failure and premature death. In DMD patients, inflammatory events secondary to dystrophin mutation play a major role in the progression of the pathology. Sertoli cells (SeC) have been largely used to protect xenogeneic engraftments or induce trophic effects thanks to their ability to secrete trophic, antiinflammatory, and immunomodulatory factors. Here we have purified SeC from specific pathogen-free (SPF)-certified neonatal pigs, and embedded them into clinical grade alginate microcapsules. We show that a single intraperitoneal injection of microencapsulated SPF SeC (SeC-MC) in an experimental model of DMD can rescue muscle morphology and performance in the absence of pharmacologic immunosuppressive treatments. Once i.p. injected, SeC-MC act as a drug delivery system that modulates the inflammatory response in muscle tissue, and upregulates the expression of the dystrophin paralogue, utrophin in muscles through systemic release of heregulin-β1, thus promoting sarcolemma stability. Analyses performed five months after single injection show high biocompatibility and long-term efficacy of SeC-MC. Our results might open new avenues for the treatment of patients with DMD and related diseases.

Xenograft of microencapsulated Sertoli cells for the cell therapy of type 2 diabetes mellitus in spontaneously diabetic nonhuman primates: preliminary data.

Insulin resistance in type 2 diabetes mellitus (T2DM) may be due to a chronic inflammation of the visceral adipose tissue (VAT) leading to local and systemic increases in proinflammatory cytokines. Microencapsulated porcine Sertoli cells (MC-pSC), by provision of immunomodulatory and trophic factors, have been successfully used to reduce such inflammation in rodent animal models of type 1 diabetes with no complications or deleterious side effects. Herein, we have begun to investigate this novel and safe therapeutic approach in the spontaneously obese nonhuman primate with spontaneous, insulin-dependent T2DM. After MC-pSC intraperitoneal injection we have evaluated, throughout a 6-month follow-up period, daily ad libitum fed glucose levels, daily exogenous insulin supplementation, biweekly body weight measurements, periodic fasting blood glucose concentrations, glycated hemoglobin (HbA1c) levels, glucose tolerance tests (GTT), and fluorescence-activated cell sorting cytometry (FACS) assessment of peripheral blood mononuclear cells. Very preliminarily, we have observed a slight reduction in fasting (FPG) and mean nonfasting (NF) plasma glucose levels. We found minimal changes, only in 1 animal, in daily exogenous insulin requirements and HbA1c levels. Flow cytometric analysis was associated with decrease in CD8(+) cells only in 1 recipient with a reduction in mean regulatory T Cells (Treg), whereas interestingly, decrease of B lymphocytes was observed in both animals. These results may suggest that this novel MC-SC-based transplantation protocol might possibly impact the metabolic status of T2DM in higher mammals that are close to humans.

Xenograft of microencapsulated Sertoli cells restores glucose homeostasis in db/db mice with spontaneous diabetes mellitus

Increased abdominal fat and chronic inflammation in the expanded adipose tissue of obesity contribute to the development of insulin resistance and type 2 diabetes mellitus (T2D). The emerging immunoregulatory and anti‐inflammatory properties of Sertoli cells have prompted their application to experimental models of autoimmune/inflammatory disorders, including diabetes.

Terapeutic Potential of Microencapsulated Sertoli Cells in Huntington Disease.

Immune dysfunction, promoted by pro‐inflammatory cytokines, plays a pivotal role in neurodegeneration associated with Huntingtons disease.

Alginates in Pharmaceutics and Biomedicine: Is the Future so Bright?

Alginate represents one of the most appealing biopolymers for pharmaceutical and biomedical applications. Alginate as a biomaterial for clinical use has been established, although not free from issues. Here we provide a critical review on some of the main recent advances in alginate research in drug delivery and its prominent role in cell microencapsulation for the treatment of diseases, such as type 1 diabetes mellitus. A brief description of the basic properties of the polymer will be provided as well. Based on our experience and contributions, as well as wide research in the field, the correlation between physicochemical and biological properties of alginate systems and clinical outcomes will be investigated and discussed to address the actual future clinical impact of alginatebased delivery strategies.