Targeting pentamidine towards CD44-overexpressing cells using hyaluronated lipid-polymer hybrid nanoparticles.

Biodegradable nanocarriers possess enormous potential for use as drug delivery systems that can accomplish controlled and targeted drug release, and a wide range of nanosystems have been reported for the treatment and/or diagnosis of various diseases and disorders. Of the various nanocarriers currently available, liposomes and polymer nanoparticles have been extensively studied and some formulations have already reached the market. However, a combination of properties to create a single hybrid system can give these carriers significant advantages, such as improvement in encapsulation efficacy, higher stability, and active targeting towards specific cells or tissues, over lipid or polymer-based platforms. To this aim, this work presents the formulation of poly(lactic-co-glycolic) acid (PLGA) nanoparticles in the presence of a hyaluronic acid (HA)-phospholipid conjugate (HA-DPPE), which was used to anchor HA onto the nanoparticle surface and therefore create an actively targeted hybrid nanosystem. Furthermore, ionic interactions have been proposed for drug encapsulation, leading us to select the free base form of pentamidine (PTM-B) as the model drug. We herein report the preparation of hybrid nanocarriers that were loaded via ion-pairing between the negatively charged PLGA and HA and the positively charged PTM-B, demonstrating an improved loading capacity compared to PLGA-based nanoparticles. The nanocarriers displayed a size of below 150 nm, a negative zeta potential of -35 mV, a core-shell internal arrangement and high encapsulation efficiency (90%). Finally, the ability to be taken up and exert preferential and receptor-mediated cytotoxicity on cancer cells that overexpress the HA specific receptor (CD44) has been evaluated. Competition assays supported the hypothesis that PLGA/HA-DPPE nanoparticles deliver their cargo within cells in a CD44-dependent manner.

Chondroitin sulfate and caseinophosphopeptides doped polyurethane-based highly porous 3D scaffolds for tendon-to-bone regeneration.

Tendon disorders are common injuries, which can be greatly debilitating as they are often accompanied by great pain and inflammation. Moreover, several problems are also related to the laceration of the tendon-to-bone interface (TBI), a specific region subjected to great mechanical stresses. The techniques used nowadays for the treatment of tendon and TBI injuries often involve surgery. However, one critical aspect of this procedure involves the elevated risk of fail due to the tissues weakening and the postoperative alterations of the normal joint mechanics. Synthetic polymers, such as thermoplastic polyurethane, are of special interest in the tissue engineering field as they allow the production of scaffolds with tunable elastic and mechanical properties, that could guarantee an effective support during the new tissue formation. Based on these premises, the aim of this work was the design and the development of highly porous 3D scaffolds based on thermoplastic polyurethane, and doped with chondroitin sulfate and caseinophosphopeptides, able to mimic the structural, biomechanical, and biochemical functions of the TBI. The obtained scaffolds were characterized by a homogeneous microporous structure, and by a porosity optimal for cell nutrition and migration. They were also characterized by remarkable mechanical properties, reaching values comparable to the ones of the native tendons. The scaffolds promoted the tenocyte adhesion and proliferation when caseinophosphopetides and chondroitin sulfate are present in the 3D structure. In particular, caseinophosphopeptides' optimal concentration for cell proliferation resulted 2.4 mg/mL. Finally, the systems evaluation in vivo demonstrated the scaffolds' safety, since they did not cause any inflammatory effect nor foreign body response, representing interesting platforms for the regeneration of injured TBI.

pH-sensitive niosomes for ATRA delivery: A promising approach to inhibit Pin1 in high-grade serous ovarian cancer.

The peptidyl-prolyl cis/trans isomerase Pin1 positively regulates numerous cancer-driving pathways, and it is overexpressed in several malignancies, including high-grade serous ovarian cancer (HGSOC). The findings that all-trans retinoic acid (ATRA) induces Pin1 degradation strongly support that ATRA treatment might be a promising approach for HGSOC targeted therapy. Nevertheless, repurposing ATRA into the clinics for the treatment of solid tumors remains an unmet need mainly due to the insurgence of resistance and its ineffective delivery. In the present study, niosomes have been employed for improving ATRA delivery in HGSOC cell lines. Characterization of niosomes including hydrodynamic diameter, ζ-potential, morphology, entrapment efficiency and stability over time and in culture media was performed. Furthermore, pH-sensitiveness and ATRA release profile were investigated to demonstrate the capability of these vesicles to release ATRA in a stimuli-responsive manner. Obtained results documented a nanometric and monodispersed samples with negative ζ-potential. ATRA was efficiently entrapped, and a substantial release was observed in the presence of acidic pH (pH 5.5). Finally, unloaded niosomes showed good biocompatibility while ATRA-loaded niosomes significantly increased ATRA Pin1 inhibitory activity, which was consistent with cell growth inhibition. Taken together, ATRA-loaded niosomes might represent an appealing therapeutic strategy for HGSOC therapy.

Cyclosporine A micellar nasal spray characterization and antiviral action against SARS-CoV-2.

The upper airways represent the point of entrance from where Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection spreads to the lungs. In the present work, α-tocopheryl-polyethylene-glycol succinate (TPGS) micelles loaded with cyclosporine A (CSA) were developed for nasal administration to prevent or treat the viral infection in the very first phases. The behavior of the micelles in presence of simulated nasal mucus was investigated in terms of stability and mucopenetration rate, evidencing long-term stability and fast diffusion across the glycoproteins matrix. Moreover, the spray characteristics of the micellar formulation and deposition profile in a silicon nasal model were studied using three nasal spray devices. Results allowed to identify the nasal spray pump (BiVax, Aptar) able to provide the wider and uniform deposition of the nasal cavity. The cyclosporine A micelles antiviral activity against SARS-CoV-2 was tested on the Omicron BA.1 variant using Vero E6 cells with protocols simulating treatment before, during and after the infection of the upper airways. Complete viral inactivation was observed for the cyclosporine-loaded micelles while a very low activity was evidenced for the non-formulated drug, suggesting a synergistic activity of the drug and the formulation. In conclusion, this work showed that the developed cyclosporine A-loaded micellar formulations have the potential to be clinically effective against a wide spectrum of coronavirus variants.

Nanoclay-Doped Electrospun Nanofibers for Tissue Engineering: Investigation on the Structural Modifications in Physiological Environment.

Background: Clay minerals are nanomaterials that have recently been recognized as enabling excipients that can promote cell adhesion, proliferation, and differentiation. When nanoclays are loaded in a 3D polymeric nanostructure, the cell-substrate interaction is enhanced, and other bioactive properties are optimized. Purpose: In this study, hectorite (HEC)- and montmorillonite (MMT)-doped polymeric scaffolds were explored for the treatment of deep and chronic skin lesions. Methods: Scaffolds were manufactured by means of electrospinning and then crosslinked by heating. Physicochemical analyses were correlated with in vitro biopharmaceutical characterization to predict the in vivo fate of the clay-doped scaffolds. Results and Discussion: The addition of MMT or HEC to the polymeric scaffold framework modifies the surface arrangement and, consequently, the potential of the scaffolds to interact with biological proteins. The presence of nanoclays alters the nanofiber morphology and size, and MMT doping increases wettability and protein adhesion. This has an impact on fibroblast behavior in a shorter time since scaffold stiffness facilitates cell adhesion and cell proliferation. Conclusion: MMT proved to perform better than HEC, and this could be related to its higher hydrophilicity and protein adhesion.

Micelles-in-Liposome Systems Obtained by Proliposomal Approach for Cannabidiol Delivery: Structural Features and Skin Penetration.

Deformable liposomes represent valuable drug carriers for cutaneous administration. Nevertheless, the fluid lipid membrane can favor the drug leakage during storage. Proliposomes may represent a suitable strategy to solve this issue. As an alternative, a novel carrier, which encloses hydrophobic drugs in the inner core of vesicles, namely, a drug-in-micelles-in-liposome system (DiMiL), has been proposed. In this work, we investigated the possible advantages of combining these two approaches to obtain a formulation able to enhance the skin penetration of cannabidiol (CBD). Proliposomes were prepared by spray-drying or slurry method testing lactose, sucrose, and trehalose as carriers at different sugar/lipid weight ratios. The ratio between soy-phosphatidylcholine (main lipid) and Tween 80 was instead fixed at 85:15 w/w. DiMiL systems were extemporaneously obtained by the hydration of proliposomes with a Kolliphor HS 15 micellar dispersion (containing CBD, when appropriate). Based on the technological properties, sucrose and trehalose at 2:1 sugar/lipid ratio resulted in the best carriers for spray-dried and "slurried" proliposomes, respectively. Cryo-EM images clearly showed the presence of micelles in the aqueous core of lipid vesicles and the presence of sugars did not alter the structural organization of DiMiL systems, as demonstrated by SAXS analyses. All formulations were highly deformable and able to control CBD release regardless of the presence of sugar. The permeation through human epidermis of CBD carried by DiMiL systems was significantly improved compared to that obtained loading the drug in conventional deformable liposomes with the same lipid composition or in an oil solution. Furthermore, the presence of trehalose led to a further slight increase of the flux. Altogether, these results demonstrated that proliposomes may be a valuable intermediate for the preparation of deformable liposome-based cutaneous dosage forms, improving the stability without compromising the overall performances.

Polysaccharide-protein microparticles based-scaffolds to recover soft tissue loss in mild periodontitis.

Periodontal regeneration is extremely limited and unpredictable due to structural complications, as it requires the simultaneous restoration of different tissues, including cementum, gingiva, bone, and periodontal ligament. In this work, spray-dried microparticles based on green materials (polysaccharides - gums - and a protein - silk fibroin) are proposed to be implanted in the periodontal pocket as 3D scaffolds during non-surgical treatments, to prevent the progression of periodontal disease and to promote the healing in mild periodontitis. Arabic or xanthan gum have been associated to silk fibroin, extracted from Bombyx mori cocoons, and loaded with lysozyme due to its antibacterial properties. The microparticles were prepared by spray-drying and cross-linked by water vapor annealing, inducing the amorphous to semi-crystalline transition of the protein component. The microparticles were characterized in terms of their chemico-physical features (SEM, size distribution, structural characterization - FTIR and SAXS, hydration and degradation properties) and preclinical properties (lysozyme release, antibacterial properties, mucoadhesion, in vitro cells adhesion and proliferation and in vivo safety on a murine incisional wound model). The encouraging preclinical results highlighted that these three-dimensional (3D) microparticles could provide a biocompatible platform able to prevent periodontitis progression and to promote the healing of soft tissues in mild periodontitis.

Ceramide present in cholangiocarcinoma-derived extracellular vesicle induces a pro-inflammatory state in monocytes.

Cholangiocarcinoma (CCA) is a rare cancer characterized by a global increasing incidence. Extracellular vesicles (EV) contribute to many of the hallmarks of cancer through transfer of their cargo molecules. The sphingolipid (SPL) profile of intrahepatic CCA (iCCA)-derived EVs was characterized by liquid chromatography-tandem mass spectrometry analysis. The effect of iCCA-derived EVs as mediators of inflammation was assessed on monocytes by flow cytometry. iCCA-derived EVs showed downregulation of all SPL species. Of note, poorly-differentiated iCCA-derived EVs showed a higher ceramide and dihydroceramide content compared with moderately-differentiated iCCA-derived EVs. Of note, higher dihydroceramide content was associated with vascular invasion. Cancer-derived EVs induced the release of pro-inflammatory cytokines in monocytes. Inhibition of synthesis of ceramide with Myriocin, a specific inhibitor of the serine palmitoyl transferase, reduced the pro-inflammatory activity of iCCA-derived EVs, demonstrating a role for ceramide as mediator of inflammation in iCCA. In conclusion, iCCA-derived EVs may promote iCCA progression by exporting the excess of pro-apoptotic and pro-inflammatory ceramides.

Cerium Oxide and Chondroitin Sulfate Doped Polyurethane Scaffold to Bridge Tendons.

Tendon disorders are common medical conditions, which can be greatly debilitating as they are often accompanied by great pain and inflammation. The techniques used nowadays for the treatment of chronic tendon injuries often involve surgery. However, one critical aspect of this procedure involves the scar tissue, characterized by mechanical properties that vary from healthy tissue, rendering the tendons inclined to reinjury or rupture. Synthetic polymers, such as thermoplastic polyurethane, are of special interest in the tissue engineering field as they allow the production of scaffolds with controlled elastic and mechanical properties, which could guarantee an effective support during the new tissue formation. The aim of this work was the design and the development of tubular nanofibrous scaffolds based on thermoplastic polyurethane and enriched with cerium oxide nanoparticles and chondroitin sulfate. The scaffolds were characterized by remarkable mechanical properties, especially when tubular aligned, reaching values comparable to the ones of the native tendons. A weight loss test was performed, suggesting a degradation in prolonged times. In particular, the scaffolds maintained their morphology and also remarkable mechanical properties after 12 weeks of degradation. The scaffolds promoted the cell adhesion and proliferation, in particular when in aligned conformation. Finally, the systems in vivo did not cause any inflammatory effect, representing interesting platforms for the regeneration of injured tendons.

Electrospun Scaffolds Based on Poly(butyl cyanoacrylate) for Tendon Tissue Engineering.

Tendon disorders are common medical conditions that could lead to significant disability, pain, healthcare costs, and a loss of productivity. Traditional approaches require long periods of treatment, and they largely fail due to the tissues weakening and the postoperative alterations of the normal joint mechanics. To overcome these limitations, innovative strategies for the treatment of these injuries need to be explored. The aim of the present work was the design of nano-fibrous scaffolds based on poly(butyl cyanoacrylate) (PBCA), a well-known biodegradable and biocompatible synthetic polymer, doped with copper oxide nanoparticles and caseinphosphopeptides (CPP), able to mimic the hierarchical structure of the tendon and to improve the tissue healing potential. These were developed as implants to be sutured to reconstruct the tendons and the ligaments during surgery. PBCA was synthetized, and then electrospun to produce aligned nanofibers. The obtained scaffolds were characterized for their structure and physico-chemical and mechanical properties, highlighting that CuO and CPP loading, and the aligned conformation determined an increase in the scaffold mechanical performance. Furthermore, the scaffolds loaded with CuO showed antioxidant and anti-inflammatory properties. Moreover, human tenocytes adhesion and proliferation to the scaffolds were assessed in vitro. Finally, the antibacterial activity of the scaffolds was evaluated using Escherichia coli and Staphylococcus aureus as representative of Gram-negative and Gram-positive bacteria, respectively, demonstrating that the CuO-doped scaffolds possessed a significant antimicrobial effect against E. coli. In conclusion, scaffolds based on PBCA and doped with CuO and CPP deserve particular attention as enhancers of the tendon tissue regeneration and able to avoid bacterial adhesion. Further investigation on the scaffold efficacy in vivo will assess their capability for enhancing the tendon ECM restoration in view of accelerating their translation to the clinic.

Neem Oil or Almond Oil Nanoemulsions for Vitamin E Delivery: From Structural Evaluation to in vivo Assessment of Antioxidant and Anti-Inflammatory Activity.

Purpose: Vitamin E (VitE) may be classified in "the first line of defense" against the formation of reactive oxygen species. Its inclusion in nanoemulsions (NEs) is a promising alternative to increase its bioavailability. The aim of this study was to compare O/W NEs including VitE based on Almond or Neem oil, showing themselves antioxidant properties. The potential synergy of the antioxidant activities of oils and vitamin E, co-formulated in NEs, was explored. Patients and Methods: NEs have been prepared by sonication and deeply characterized evaluating size, ζ-potential, morphology (TEM and SAXS analyses), oil nanodroplet feature, and stability. Antioxidant activity has been evaluated in vitro, in non-tumorigenic HaCaT keratinocytes, and in vivo through fluorescence analysis of C. elegans transgenic strain. Moreover, on healthy human volunteers, skin tolerability and anti-inflammatory activity were evaluated by measuring the reduction of the skin erythema induced by the application of a skin chemical irritant (methyl-nicotinate). Results: Results confirm that Vitamin E can be formulated in highly stable NEs showing good antioxidant activity on keratinocyte and on C. elegans. Interestingly, only Neem oil NEs showed some anti-inflammatory activity on healthy volunteers. Conclusion: From the obtained results, Neem over Almond oil is a more appropriate candidate for further studies on this application.

Ultrastable shelled PFC nanobubbles: A platform for ultrasound-assisted diagnostics, and therapy.

Nanoscale echogenic bubbles (NBs), can be used as a theranostic platform for the localized delivery of encapsulated drugs. However, the generation of NBs is challenging, because they have lifetimes as short as milliseconds in solution. The aim of this work has been the optimization of a preparation method for the generation of stable NBs, characterized by measuring: a) acoustic efficiency, b) nano-size, to ensure passive tumour targeting, c) stability during storage and after injection and d) ability to entrap drugs. NBs are monodisperse and ultra-stable, their stability achieved by generation of an amphiphilic multilamellar shell able to efficiently retain the PFC gas. The NBs perform as good acoustic enhancers over a wide frequency range and out of resonant conditions, as tested in both in vitro and in vivo experiments, proving to be a potential platform for the production of versatile carriers to be used in ultrasound-assisted diagnostic, therapeutic and theranostic applications.

Topographical and Compositional Gradient Tubular Scaffold for Bone to Tendon Interface Regeneration.

The enthesis is an extremely specific region, localized at the tendon-bone interface (TBI) and made of a hybrid connection of fibrocartilage with minerals. The direct type of enthesis tissue is commonly subjected to full laceration, due to the stiffness gradient between the soft tissues and hard bone, and this often reoccurs after surgical reconstruction. For this purpose, the present work aimed to design and develop a tubular scaffold based on pullulan (PU) and chitosan (CH) and intended to enhance enthesis repair. The scaffold was designed with a topographical gradient of nanofibers, from random to aligned, and hydroxyapatite (HAP) nanoparticles along the tubular length. In particular, one part of the tubular scaffold was characterized by a structure similar to bone hard tissue, with a random mineralized fiber arrangement; while the other part was characterized by aligned fibers, without HAP doping. The tubular shape of the scaffold was also designed to be extemporarily loaded with chondroitin sulfate (CS), a glycosaminoglycan effective in wound healing, before the surgery. Micro CT analysis revealed that the scaffold was characterized by a continuous gradient, without interruptions from one end to the other. The gradient of the fiber arrangement was observed using SEM analysis, and it was still possible to observe the gradient when the scaffold had been hydrated for 6 days. In vitro studies demonstrated that human adipose stem cells (hASC) were able to grow and differentiate onto the scaffold, expressing the typical ECM production for tendon in the aligned zone, or bone tissue in the random mineralized part. CS resulted in a synergistic effect, favoring cell adhesion/proliferation on the scaffold surface. These results suggest that this tubular scaffold loaded with CS could be a powerful tool to support enthesis repair upon surgery.

Dysmyelination and glycolipid interference caused by phenylalanine in phenylketonuria.

Phenylketonuria (PKU) is a metabolic disorder connected to an excess of phenylalanine (Phe) in the blood and tissues, with neurological consequences. The disease's molecular bases seem to be related to the accumulation of Phe at the cell membrane surface. Radiological outcomes in the brain demonstrate decreased water diffusivity in white matter, involving axon dysmyelination of not yet understood origin. We used a biophysical approach and model membranes to extend our knowledge of Phe-membrane interaction by clarifying Phe's propensity to affect membrane structure and dynamics based on lipid composition, with emphasis on modulating cholesterol and glycolipid components to mimic raft domains and myelin sheath membranes. Phe showed affinity for the investigated membrane mimics, mainly affecting the Phe-facing membrane leaflet. The surfaces of our neuronal membrane raft mimics were strong anchoring sites for Phe, showing rigidifying effects. From a therapeutic perspective, we further investigated the role of doxycycline, known to disturb Phe packing, unveiling its action as a competitor in Phe interactions with the membrane, suggesting its potential for treatment in the early stages of PKU. Our results suggest how Phe accumulation in extracellular fluids can impede normal growth of myelin sheaths by interfering with membrane slipping and by remodulating free water and myelin-associated water contents.

Smart nano-in-microparticles to tackle bacterial infections in skin tissue engineering.

Chronic wounds (resulting from underlying disease, metabolic disorders, infections, trauma, and even tumours) pose significant health problems. In this work, microparticles, based on polysaccharides (maltodextrin or dextran) and amino acids, and doped with antibacterial nanoparticles (CuO or ZnO NPs) are designed. Smart nano-in-microparticles with a hierarchical 3D structure are developed. The ultimate goal aims at an innovative platform to achieve skin repair and to manage skin colonization by avoiding infection that could delay and even impair the healing process. The microparticles are prepared by spray-drying and cross-linked by heating, to obtain insoluble scaffolds able to facilitate cell proliferation in the wound bed. The nano-in-microparticles are characterized using a multidisciplinary approach: chemico-physical properties (SEM, SEM-EDX, size distribution, swelling and degradation properties, structural characterization - FTIR, XRPD, SAXS - mechanical properties, surface zeta potential) and preclinical properties (in vitro biocompatibility and whole-blood clotting properties, release studies and antimicrobial properties, and in vivo safety and efficacy on murine burn/excisional wound model) were assessed. The hierarchical 3D nano-in microparticles demonstrate to promote skin tissue repair in a preclinical study, indicating that this platform deserves particular attention and further investigation will promote the prototypes translation to clinics.

Biochemical and biophysical features of disease-associated tau mutants V363A and V363I.

The comprehension of pathogenetic mechanisms in tauopathy-associated neurodegenerative diseases can be improved by the knowledge of the biochemical and biophysical features of mutated tau proteins. Here, we used the full-length, wild-type tau, the V363A and V363I mutated species, associated with pathology, and the P301L mutated tau as a benchmark. Using several techniques, including small-angle X-ray scattering, atomic force microscopy, thioflavin T binding, and electrophoretic separation, we compared their course from intrinsically disordered monomers in solution to early-stage recruitment in complexes and then aggregates of increasing size over long periods up to the asymptotic aggregative behavior of full-length tau proteins. We showed that diversity in the kinetics of recruitment and aggregate structure occurs from the beginning and spreads all over their pathway to very large objects. The different extents of conformational changes and types of molecular assemblies among the proteins were also reflected in their in vitro toxicity; this variation could correlate with physiopathology in humans, considering that the P301L mutation is more aggressive than V363A, especially V363I. This study identified the presence of aggregation intermediates and corroborated the oligomeric hypothesis of tauopathies.

Polystyrene perturbs the structure, dynamics, and mechanical properties of DPPC membranes: An experimental and computational study.

Synthetic plastic oligomers can interact with the cells of living organisms by different ways. They can be intentionally administered to the human body as part of nanosized biomedical devices. They can be inhaled by exposed workers, during the production of multicomponent, polymer-based nanocomposites. They can leak out of food packaging. Most importantly, they can result from the degradation of plastic waste, and enter the food chain. A physicochemical characterization of the effects of synthetic polymers on the structure and dynamics of cell components is still lacking. Here, we combine a wide spectrum of experimental techniques (calorimetry, x-ray, and neutron scattering) with atomistic Molecular Dynamics simulations to study the interactions between short chains of polystyrene (25 monomers) and model lipid membranes (DPPC, in both gel and fluid phase). We find that doping doses of polystyrene oligomers alter the thermal properties of DPPC, stabilizing the fluid lipid phase. They perturb the membrane structure and dynamics, in a concentration-dependent fashion. Eventually, they modify the mechanical properties of DPPC, reducing its bending modulus in the fluid phase. Our results call for a systematic, interdisciplinary assessment of the mechanisms of interaction of synthetic, everyday use polymers with cell membranes.

Smart Device for Biologically Enhanced Functional Regeneration of Osteo-Tendon Interface.

The spontaneous healing of a tendon laceration results in the formation of scar tissue, which has lower functionality than the original tissue. Moreover, chronic non-healing tendon injuries frequently require surgical treatment. Several types of scaffolds have been developed using the tissue engineering approach, to complement surgical procedures and to enhance the healing process at the injured site. In this work, an electrospun hybrid tubular scaffold was designed to mimic tissue fibrous arrangement and extracellular matrix (ECM) composition, and to be extemporaneously loaded into the inner cavity with human platelet lysate (PL), with the aim of leading to complete post-surgery functional regeneration of the tissue for functional regeneration of the osteo-tendon interface. For this purpose, pullulan (P)/chitosan (CH) based polymer solutions were enriched with hydroxyapatite nanoparticles (HP) and electrospun. The nanofibers were collected vertically along the length of the scaffold to mimic the fascicle direction of the tendon tissue. The scaffold obtained showed tendon-like mechanical performance, depending on HP content and tube size. The PL proteins were able to cross the scaffold wall, and in vitro studies have demonstrated that tenocytes and osteoblasts are able to adhere to and proliferate onto the scaffold in the presence of PL; moreover, they were also able to produce either collagen or sialoproteins, respectively-important components of ECM. These results suggest that HP and PL have a synergic effect, endorsing PL-loaded HP-doped aligned tubular scaffolds as an effective strategy to support new tissue formation in tendon-to-bone interface regeneration.

Hyaluronic Acid-Dexamethasone Nanoparticles for Local Adjunct Therapy of Lung Inflammation.

The delivery of a dexamethasone formulation directly into the lung appears as an appropriate strategy to strengthen the systemic administration, reducing the dosage in the treatment of lung severe inflammations. For this purpose, a hyaluronic acid-dexamethasone formulation was developed, affording an inhalable reconstituted nanosuspension suitable to be aerosolized. The physico-chemical and biopharmaceutical properties of the formulation were tested: size, stability, loading of the spray-dried dry powder, reconstitution capability upon redispersion in aqueous media. Detailed structural insights on nanoparticles after reconstitution were obtained by light and X-ray scattering techniques. (1) The size of the nanoparticles, around 200 nm, is in the proper range for a possible engulfment by macrophages. (2) Their structure is of the core-shell type, hosting dexamethasone nanocrystals inside and carrying hyaluronic acid chains on the surface. This specific structure allows for nanosuspension stability and provides nanoparticles with muco-inert properties. (3) The nanosuspension can be efficiently aerosolized, allowing for a high drug fraction potentially reaching the deep lung. Thus, this formulation represents a promising tool for the lung administration via nebulization directly in the pipe of ventilators, to be used as such or as adjunct therapy for severe lung inflammation.

Structure and Fate of Nanoparticles Designed for the Nasal Delivery of Poorly Soluble Drugs.

Nanoparticles are promising mediators to enable nasal systemic and brain delivery of active compounds. However, the possibility of reaching therapeutically relevant levels of exogenous molecules in the body is strongly reliant on the ability of the nanoparticles to overcome biological barriers. In this work, three paradigmatic nanoformulations vehiculating the poorly soluble model drug simvastatin were addressed: (i) hybrid lecithin/chitosan nanoparticles (LCNs), (ii) polymeric poly-ε-caprolactone nanocapsules stabilized with the nonionic surfactant polysorbate 80 (PCL_P80), and (iii) polymeric poly-ε-caprolactone nanocapsules stabilized with a polysaccharide-based surfactant, i.e., sodium caproyl hyaluronate (PCL_SCH). The three nanosystems were investigated for their physicochemical and structural properties and for their impact on the biopharmaceutical aspects critical for nasal and nose-to-brain delivery: biocompatibility, drug release, mucoadhesion, and permeation across the nasal mucosa. All three nanoformulations were highly reproducible, with small particle size (∼200 nm), narrow size distribution (polydispersity index (PI) < 0.2), and high drug encapsulation efficiency (>97%). Nanoparticle composition, surface charge, and internal structure (multilayered, core-shell or raspberry-like, as assessed by small-angle neutron scattering, SANS) were demonstrated to have an impact on both the drug-release profile and, strikingly, its behavior at the biological interface. The interaction with the mucus layer and the kinetics and extent of transport of the drug across the excised animal nasal epithelium were modulated by nanoparticle structure and surface. In fact, all of the produced nanoparticles improved simvastatin transport across the epithelial barrier of the nasal cavity as compared to a traditional formulation. Interestingly, however, the permeation enhancement was achieved via two distinct pathways: (a) enhanced mucoadhesion for hybrid LCN accompanied by fast mucosal permeation of the model drug, or (b) mucopenetration and an improved uptake and potential transport of whole PCL_P80 and PCL_SCH nanocapsules with delayed boost of permeation across the nasal mucosa. The correlation between nanoparticle structure and its biopharmaceutical properties appears to be a pivotal point for the development of novel platforms suitable for systemic and brain delivery of pharmaceutical compounds via intranasal administration.