In vitro and in vivo applications of a universal and synthetic thermo-responsive drug delivery hydrogel platform.

A synthetic and thermo-responsive polymer, poly(N-isopropylacrylamide)-co-(polylactide/2-hydroxy methacrylate)-co-(oligo (ethylene glycol)), is used to formulate a universal carrier platform for sustained drug release. The enabling carrier, denoted as TP, is prepared by dissolving the polymer in an aqueous solution at a relatively neutral pH. A wide range of therapeutic moieties can be incorporated without the need for the addition of surfactants, organic solvents, and other reagents to the carrier system. The resulting solution is flowable through fine gauge needle, allowing accurate administration of TP to the target site. After injection, TP carrier undergoes a coil to globe phase transition to form a hydrogel matrix at the site. The benign nature of the polymer carrier and its physical gelation process are essential to preserve the biological activity of the encapsulated compounds while the adhesive hydrogel nature of the matrix allows sustained elusion and controlled delivery of the incorporated therapeutics. The TP carrier system has been shown to be non-toxic and elicits a minimal inflammatory response in multiple in vitro studies. These findings suggest the suitability of TP as an enabling carrier of therapeutics for localized and sustained drug delivery. To confirm this hypothesis, the capabilities of TP to encapsulate and effectively deliver multiple therapeutics of different physicochemical characteristics was evaluated. Specifically, a broad range of compounds were tested, including ciprofloxacin HCl, tumor necrosis factor-alpha (TNF-α), transforming growth factor beta 1 (TGF-ß1), and recombinant human bone morphogenetic protein 2 (BMP2). In vitro studies confirmed that TP carrier is able to control the release of the encapsulated drugs over an extended period of time and mitigate their burst release regardless of the compounds' physiochemical properties for the majority of the loaded therapeutics. Importantly, in vitro and in vivo animal studies showed that the released drugs from the TP hydrogel matrix remained potent and bioactive, confirming the high potential of the TP polymer system as an enabling carrier.

Prospective nanoparticle treatments for lymphangioleiomyomatosis.

INTRODUCTION: Lymphangioleiomyomatosis (LAM) is a rare lung disease that is characterized by smooth muscle-like cell growth in the lungs. The current available oral treatment rapamycin slows down the disease progression but does not result in a cure. Rapamycin is also limited by its low bioavailability and dose-related adverse side effects. New treatments are, therefore, underway to investigate alternative targets and combination therapies for LAM. In recent years, much focus has been on the development of therapies based on inhaled nanotechnology using carriers to deliver drugs, as it is shown to improve drug solubility, local targeted treatment, and bioavailability. AREAS COVERED: This review, therefore, focuses on future prospective treatments for LAM using nanoparticles and lipid-based nanocarriers, including liposomes, solid lipid nanoparticles, micelles, and polymeric nanoparticles. It also investigates how nanoparticles' physicochemical factors such as size and charge can affect the treatment of both pulmonary and extrapulmonary LAM. EXPERT OPINION: Advanced clinical research is still needed to demonstrate the full potential and drive future commercialization of LAM treatments delivered via inhaled lipid nanobased formulations. If successful, the resultant effects will be seen in the improvement in the life expectancy and life quality of LAM patients.

Properties of rapamycin solid lipid nanoparticles for lymphatic access through the lungs & part I: the effect of size.

Background: Lymphangioleiomyomatosis (LAM) is characterized by growth of smooth muscle-like cells in the lungs that spread to other organs via lymphatic vessels. Current oral rapamycin treatment is limited by low bioavailability of approximately 15%. Aim: The effect of inhaled rapamycin solid lipid nanoparticles (Rapa-SLNs) size on its penetration through the lymphatics. Method: Three Rapa-SLN formulations (200-1000 nm) were produced and assessed for particle characteristics and further for toxicity and performance in vitro. Results: Rapa-SLNs of 200 nm inhibited proliferation in TSC2-negative mouse embryonic fibroblast cells and penetrated the respiratory epithelium and lymphatic endothelium significantly faster compared with free rapamycin and larger Rapa-SLNs. Conclusion: Rapa-SLN approximately 200 nm allows efficient entry of rapamycin into the lymphatic system and is therefore a promising treatment for LAM patients.

Properties of rapamycin solid lipid nanoparticles for lymphatic access through the lungs & part II: the effect of nanoparticle charge.

Aim: Lymphangioleiomyomatosis is characterized by smooth muscle-like cells in the lungs that spread to other organs via lymphatic vessels. Oral rapamycin is restricted by low bioavailability approximately 15%. The aim of the present study is to systematically investigate the effect of inhaled rapamycin solid lipid nanoparticles (Rapa-SLN) surface charge on efficacy and penetration into the lymphatics. Materials & methods: Rapa-SLN formulations with different charge: neutral, positive and negative, were produced and assessed for their physicochemical particle characteristics and efficacy in vitro. Results: Negative Rapa-SLNs were significantly faster at entering the lymphatic endothelium and more potent at inhibiting lymphanigiogenesis compared with neutral and positive Rapa-SLNs. Conclusion: Negative Rapa-SLNs showed efficient lymphatic access and should therefore be investigated further as a treatment for targeting extrapulmonary lymphangioleiomyomatosis.

Inhaled rapamycin solid lipid nano particles for the treatment of Lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare lung disease characterized by uncontrolled growth of smooth muscle -like cells in the lungs that can spread via the lymphatic system to other parts of the body. The current treatment for LAM, oral rapamycin, is limited by its low oral bioavailability and side effects. This study aims to develop an inhaled formulation of rapamycin solid lipid nanoparticles (Rapa-SLNs) to avoid first-pass metabolism, increase invivo half-life and facilitate entry into the lymphatic system through the lungs. Rapa-SLNs were manufactured using a hot evaporation technique and freeze-dried overnight with 5% (w/v) mannitol and before being assessed further for particle characteristics and in vitro aerosol performance and release. The formulation's ability to penetrate through bronchial epithelial layer was evaluated using a Calu-3 cell model, while its ability to interfere with the LAM intracellular cascade was evaluated using Mouse Embryonic fibroblast (MEF) cells deficient for the tuberous sclerosis complex 2 (TSC2) and compared with rapamycin solution. Results showed that the Rapa- SLNs had the appropriate size (237.5 ±â€¯1.8 nm), charge (-11.2), in vitro aerosol performance (MMAD=5.4 ±â€¯0.4 µm) and sustained release profile suitable for entry into the lymphatic system via the pulmonary route. Additionally, the nanoparticles were transported at a faster rate across the bronchial epithelial layer compared to free rapamycin solution. The formulation also showed similar mTOR (mammalian target of Rapamycin) inhibition properties compared to free rapamycin, and was able to significantly decrease the amount of proliferation in TSC2 negative MEF cells. This formulation is therefore a promising alternative treatment for LAM patients, as it could potentially reduce problems associated with low bioavailability and side effects of current oral treatment.

Simvastatin Nanoparticles Reduce Inflammation in LPS-Stimulated Alveolar Macrophages.

Simvastatin (SV) is widely used as a lipid-lowering medication that has also been found to have beneficial immunomodulatory effects for treatment of chronic lung diseases. Although its anti-inflammatory activity has been investigated, its underlying mechanisms have not yet been clearly elucidated. In this study, the anti-inflammatory and antioxidant effects and mechanism of simvastatin nanoparticles (SV-NPs) on lipopolysaccharide-stimulated alveolar macrophages (AMs) NR8383 cells were investigated. Quantitative cellular uptake of SV-NPs, the production of inflammatory mediators (interleukin-6, tumor necrosis factor, and monocyte chemoattractant protein-1), and oxidative stress (nitric oxide) were tested. Furthermore, the involvement of the nuclear factor κB (NF-κB) signaling pathway in activation of inflammation in AMs and the efficacy of SV were visualized using immunofluorescence. Results indicated that SV-NPs exhibit a potent inhibitory effect on nitric oxide production and secretion of inflammatory cytokine in inflamed AM, without affecting cell viability. The enhanced anti-inflammatory activity of SV-NPs is likely due to SV-improved chemical-physical stability and higher cellular uptake into AM. The study also indicates that SV targets the inflammatory and oxidative response of AM, through inactivation of the NF-κB signaling pathway, supporting the pharmacological basis of SV for treatment of chronic inflammatory lung diseases.