Andrea Ballerini

Three-dimensional printed polymeric system to encapsulate human mesenchymal stem cells differentiated into islet-like insulin-producing aggregates for diabetes treatment

Diabetes is one of the most prevalent, costly, and debilitating diseases in the world. Pancreas and islet transplants have shown success in re-establishing glucose control and reversing diabetic complications. However, both are limited by donor availability, need for continuous immunosuppression, loss of transplanted tissue due to dispersion, and lack of vascularization. To overcome the limitations of poor islet availability, here, we investigate the potential of bone marrow–derived mesenchymal stem cells differentiated into islet-like insulin-producing aggregates. Islet-like insulin-producing aggregates, characterized by gene expression, are shown to be similar to pancreatic islets and display positive immunostaining for insulin and glucagon. To address the limits of current encapsulation systems, we developed a novel three-dimensional printed, scalable, and potentially refillable polymeric construct (nanogland) to support islet-like insulin-producing aggregates’ survival and function in the host body. In vitro studies showed that encapsulated islet-like insulin-producing aggregates maintained viability and function, producing steady levels of insulin for at least 4 weeks. Nanogland—islet-like insulin-producing aggregate technology here investigated as a proof of concept holds potential as an effective and innovative approach for diabetes cell therapy.

3D Printed Vascularized Device for Subcutaneous Transplantation of Human Islets

Transplantation of pancreatic islets or stem cell derived insulin secreting cells is an attractive treatment strategy for diabetes. However, islet transplantation is associated with several challenges including function-loss associated with dispersion and limited vascularization as well as the need for continuous immunosuppression. To overcome these limitations, here we present a novel 3D printed and functionalized encapsulation system for subcutaneous engraftment of islets or islet like cells. The devices were 3D printed with polylactic acid and the surfaces treated and patterned to increase the hydrophilicity, cell attachment, and proliferation. Surface treated encapsulation systems were implanted with growth factor enriched platelet gel, which helped to create a vascularized environment before loading human islets. The device protected the encapsulated islets from acute hypoxia and kept them functional. The adaptability of the encapsulation system was demonstrated by refilling some of the experimental groups transcutaneously with additional islets.

Sustained zero-order delivery of GC-1 from a nanochannel membrane device alleviates metabolic syndrome

Background/Objectives:Our objective was to assess the sustained, low-dose and constant administration of the thyroid receptor-β (TRβ)-selective agonist GC-1 (sobetirome) from a novel nanochannel membrane device (NMD) for drug delivery. As it known to speed up metabolism, accomplish weight loss, improve cholesterol levels and possess anti-diabetic effects, GC-1 was steadily administered by our NMD, consisting of an implantable nanochannel membrane, as an alternative to conventional daily administration, which is subject to compliance issues in clinical settings.Subjects/Methods:Diet-induced obese C57BL/J6 male mice were fed a very high-fat diet (VHFD) and received NMD implants subcutaneously. Ten mice per group received capsules containing GC-1 or phosphate-buffered saline (control). Weight, lean and fat mass, as well as cholesterol, triglycerides, insulin and glucose, were monitored for 24 days. After treatment, plasma levels of thyroid-stimulating hormone (TSH) and thyroxine were compared. mRNA levels of a panel of thermogenic markers were examined using real-time PCR in white adipose tissue (WAT) and brown adipose tissue (BAT). Adipose tissue, liver and local inflammatory response to the implant were examined histologically. Pancreatic islet number and β-cell area were assessed.Results:GC-1 released from the NMD reversed VHFD-induced obesity and normalized serum cholesterol and glycemia. Significant reductions in body weight and fat mass were observed within 10 days, whereas reductions in serum cholesterol and glucose levels were seen within 7 days. The significant decrease in TSH was consistent with TRβ selectivity for GC-1. Levels of transcript for Ucp1 and thermogenic genes PGC1a, Cidea, Dio2 and Cox5a showed significant upregulation in WAT in NMD–GC-1-treated mice, but decreased in BAT. Although mice treated by NMD–GC-1 showed a similar number of pancreatic islets, they exhibited significant increase in β-cell area.Conclusions:Our data demonstrate that the NMD implant achieves steady administration of GC-1, offering an effective and tightly controlled molecular delivery system for treatment of obesity and metabolic disease, thereby addressing compliance.

A pharmacokinetic study of GC-1 delivery using a nanochannel membrane device

This study demonstrated a nanochannel membrane device (NMD) for controlled and sustained release of GC-1 in rats, in the context of the treatment of metabolic syndrome. Release profiles were established in vitro both with and without 5% labrasol for over 2 months. In vivo pharmacokinetic evaluation showed effective GC-1 plasma concentrations, which resulted in significant reductions in body weight after just one week of treatment when compared to the NMD releasing vehicle only (PBS). We also provided evidence that rats treated with NMD-GC-1 present sub-active thyroids and clear differences in the morphology of the epithelium and follicles as compared to the controls, while the heart showed changes in weight. Moreover, body temperatures remained stable throughout treatment, and glucose, pancreatic islet size, and liver histology appeared similar between the treated and control groups. Prolonged constant administration of GC-1 from the NMD proved to be a valid strategy to facilitate weight loss.

Remote magnetic switch off microgate for nanofluidic drug delivery implants

In numerous pathologies, implantable drug delivery devices provide advantages over conventional oral or parenteral approaches. Based on the site of implantation and release characteristics, implants can afford either systemic delivery or local administration, whereby the drug is delivered at or near the site of intended action. Unfortunately, current implantable drug delivery systems provide limited options for intervention in the case of an adverse reaction to the drug or the need for dosage adjustment. In the event that drug delivery must be terminated, an urgent surgical retrieval may be the only reliable option. This could be a time sensitive and costly effort, requiring access to trained professionals and emergency medical facilities. To address such limitations, here we demonstrate, in vitro and ex vivo, a novel microsystem for the rapid and effective switch off of drug delivery from an implantable nanofluidic system, by applying a safe external electromagnetic field in the FDA approved dose range. This study represents a proof of concept for a technology with potential for broad applicability to reservoir-based delivery implants for both complete interruption or remote titration of drug administration.

Transcutaneously refillable nanofluidic implant achieves sustained level of tenofovir diphosphate for HIV pre-exposure prophylaxis

ABSTRACT Pre‐exposure prophylaxis (PrEP) with antiretroviral (ARV) drugs are effective at preventing human immunodeficiency virus (HIV) transmission. However, implementation of PrEP presents significant challenges due to poor user adherence, low accessibility to ARVs and multiple routes of HIV exposure. To address these challenges, we developed the nanochannel delivery implant (NDI), a subcutaneously implantable device for sustained and constant delivery of tenofovir alafenamide (TAF) and emtricitabine (FTC) for HIV PrEP. Unlike existing drug delivery platforms with finite depots, the NDI incorporates ports allowing for transcutaneous refilling upon drug exhaustion. NDI‐mediated drug delivery in rhesus macaques resulted in sustained release of both TAF and FTC for 83 days, as indicated by concentrations of TAF, FTC and their respectively metabolites in plasma, PBMCs, rectal mononuclear cells and tissues associated with HIV transmission. Notably, clinically relevant preventative levels of tenofovir diphosphate were achieved as early as 3 days after NDI implantation. We also demonstrated the feasibility of transcutaneous drug refilling to extend the duration of PrEP drug delivery in NHPs. Overall, the NDI represents an innovative strategy for long‐term HIV PrEP administration in both developed and developing countries. Graphical abstract Figure. No caption available. HighlightsRefillable nanofluidic implant achieves preventive level of tenofovir diphosphate for HIV pre‐exposure prophylaxis.

Nanofluidic drug-eluting seed for sustained intratumoral immunotherapy in triple negative breast cancer

ABSTRACT Conventional systemic immunotherapy administration often results in insufficient anti‐tumor immune response and adverse side effects. Delivering immunotherapeutics intratumorally could maximize tumor exposure, elicit efficient anti‐tumor immune response, and minimize toxicity. To fulfill the unmet clinical need for sustained local drug delivery and to avoid repeated intratumoral injections, we developed a nanofluidic‐based device for intratumoral drug delivery called the nanofluidic drug‐eluting seed (NDES). The NDES is inserted intratumorally using a minimally invasive trocar method similar to brachytherapy seed insertion and offers a clinical advantage of drug elution. Drug diffusion from the NDES is regulated by physical and electrostatic nanoconfinement, thereby resulting in constant and sustained immunotherapeutic delivery without the need for injections or clinician intervention. In this study, the NDES was used to deliver immunotherapeutics intratumorally in the 4T1 orthotopic murine mammary carcinoma model, which recapitulates triple negative breast cancer. We demonstrated that NDES‐mediated intratumoral release of agonist monoclonal antibodies, OX40 and CD40, resulted in potentiation of local and systemic anti‐tumor immune response and inhibition of tumor growth compared to control mice. Further, mice treated with NDES‐CD40 demonstrated minimal liver damage compared to systemically treated mice. Collectively, our study highlights the NDES as an effective platform for sustained intratumoral immunotherapeutic delivery. The potential clinical impact is tremendous given that the NDES is applicable to a broad spectrum of drugs and solid tumors.

Efficacy of sustained delivery of GC-1 from a Nanofluidic system in a spontaneously obese non-human primate: a case study

With nearly 40% of U.S. adults obese, and childhood and adolescent rates rising, obesity and associated comorbidities are serious public health concerns with massive societal costs. Often, lifestyle interventions do not offer sufficient weight loss to improve health, requiring surgery and medications as adjunct management strategies. Here, we present a 4-month case study in which the sustained, low-dose, and constant administration of the thyroid receptor β selective agonist GC-1 (sobetirome) from a novel nanochannel membrane implant was assessed in an obese, pre-diabetic rhesus macaque. Dramatic loss of white adipose tissue in the abdomen from 36 to 18% was observed via magnetic resonance imaging in conjunction with normalized serum insulin and glycemia, with no signs of cardiotoxicity shown. The non-human primate study highlights sustained low-dose delivery of GC-1 from our minimally invasive subcutaneous implant as a valuable approach to induce weight loss and manage obesity and comorbidities, including type 2 diabetes.

Local and sustained delivery of tamoxifen for the prevention of ER+ breast cancer using a nanochannel delivery platform

A high incidence (∼75%) of primary breast cancers are estrogen receptor positive (ER+), and a large fraction of these patients can pursue chemopreventive therapies. However, due to adverse side effects, only 5% to 20% of the women at high risk who could benefit from chemotherapeutics enroll in preventive treatment. There is a clear need for alternative preventive strategies that minimize side effects and improve enrollment and compliance. Selective estrogen receptor modulators, such as tamoxifen (TMX), have been shown to reduce ER+ breast cancer incidence by up to 50% among high-risk women. Importantly, along with raloxifene, it is one of only two FDA-approved drugs for breast cancer prevention. TMX has been in use for over 40 years and has a proven record in pre- and post-menopausal women. However, the drug is marred by side effects, the most common being symptoms of menopause. Further, women treated systemically and chronically with TMX were found to have an increased incidence of endometrial carcinoma. Although rare, this side effect, along with other serious adverse effects (such as blood clots, strokes, and cataracts), has resulted in a debate concerning TMX use in cancer prevention. As the key for breast cancer chemoprevention relies upon long-term delivery of drugs while circumventing side effects, we have developed a novel local delivery strategy for the constant and sustained administration of TMX. We maintain a long-term, local release of TMX in mammary tissues by utilizing a novel implantable nanochannel Delivery System (nDS). The nDS consists of a bioinert, implantable, and mechanically robust silicon membrane which houses an exact number of densely packed slit-nanochannels as small as 2.5 nm with tight tolerances on size, geometry, and surface properties. Providing steady levels of TMX at the mammary gland target through nDS delivery maximizes the therapeutic index while limiting the unwanted secondary effects, which will ultimately improve patient compliance. In this work we chemically induced tumorigenesis in Sprague-Dawley rats by N-methyl-N-nitrosourea (NMU) injection to promote development of estrogen-dependent tumors. We performed ovariectomies seven days after NMU injection to mimic post-menopausal biology. nDS implants loaded with either TMX or PEG400 (negative control) were inserted under the left abdominal mammary gland to determine effects of nDS-TMX on tumor growth and biomarkers. Utilizing LC/MS we were able to determine the amount of TMX released from the nDS. Rats were examined for palpable tumors to assess breast tumor incidence, latency to onset, and multiplicity. Our results show that the nDS implant enables the effective delivery of TMX in this breast tumor model. Further, this technology has the potential to rapidly provide long-term breast cancer protection with significant improvement in the quality of life of patients at high risk, thereby saving thousands of lives every year. Citation Format: Carly S. Filgueira, Eugenia Nicolov, Andrea Ballerini, R. Lyle Hood, Priya Jain, Giacomo Bruno, Alessandro Grattoni. Local and sustained delivery of tamoxifen for the prevention of ER+ breast cancer using a nanochannel delivery platform. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1320.