A Hyaluronic Acid-Based Formulation with Simultaneous Local Drug Delivery and Antioxidant Ability for Active Viscosupplementation

The interplay between hyaluronic acid and stem cell secretome boosts pulmonary differentiation in 3D biomimetic microenvironments

Mesenchymal stem cells (MCSs) secretome provide MSC-like therapeutic effects in preclinical models of lung injury, circumventing safety concerns with the use of live cells. Secretome consists of Extracellular Vesicles (EVs), including populations of nano- to micro-sized particles (exosomes and microvesicles) delimited by a phospholipidic bilayer. However, its poor stability and bioavailability severely limit its application. The role of Hyaluronic acid (HA) as potential carrier in biomedical applications has been widely demonstrated. Here, we investigated the interplay between HA and MSCs- secretome blends and their ability to exert a bioactive effect on pulmonary differentiation in a 3D microenvironment mimicking lung niche. To this aim, the physical-chemical properties of HA/Secre blends have been characterized at low, medium and high HA Molecular Weights (MWs), by means of SEM/TEM, DLS, confocal microscopy and FTIR. Collectively physical-chemical properties highlight the interplay between the HA and the EVs. In 3D matrices, HA/Secre blends showed to promote differentiation in pulmonary lineage, improved as the MW of the HA in the blends decreased. Finally, HA/Secre blends' ability to cross an artificial mucus has been demonstrated. Overall, this work provides new insights for the development of future devices for the therapy of respiratory diseases that are still unmet.

Melatonin hyalurosomes in collagen thermosensitive gel as a potential repurposing approach for rheumatoid arthritis management via the intra-articular route

Despite the fact that several rheumatoid arthritis treatments have been utilized, none of them achieved complete joint healing and has been accompanied by several side effects that compromise patient compliance. This study aims to provide an effective safe RA treatment with minimum side effects through the encapsulation of melatonin (MEL) in hyalurosomes and loading these hyalurosomes in collagen thermos-sensitive poloxamer 407 (PCO) hydrogels, followed by their intra-articular administration in AIA model rats. In vitro characterization of MEL-hyalurosomes and PCO hydrogel along with in vivo evaluation of the selected formulation were conducted. Particle size, PDI and EE % of the selected formulation were 71.5 nm, 0.09 and 90 %. TEM micrographs demonstrated that the particles had spherical shape with no aggregation signs. Loading PCO hydrogels with MEL-hyalurosomes did not cause significant changes in pH although it increased its viscosity and injection time. FTIR analysis showed that no interactions were noted among the delivery system components. In vivo results revealed the superior effect of MEL-hyalurosomes PCO hydrogel over MEL-PCO hydrogel and blank PCO hydrogels in improving joint healing, cartilage repair, pannus formation and cell infiltrations. Also, MEL-hyalurosomes PCO hydrogel group showed comparable levels of TNF-α, IL1, MDA, NRF2 and HO-1 with the negative control group. These findings highlight the MEL encapsulation role in augmenting its pharmacological effects along with the synergistic effect of hyaluronic acid in hyalurosomes and collagen in PCO hydrogel in promoting joint healing.

A Meta-Analytical Way of Systematizing the Use of Hyaluronan Gels for the Relief of Osteoarthritis, Compared with New Treatment Alternatives

Hyaluronic acid, in the form of a gel or viscoelastic colloidal solution, is currently used for the viscosupplementation of joints affected by osteoarthritis, but its effectiveness is under debate in relation to newer alternatives. Based on meta-analytical arguments, the present article reinforces the opinion that there are still no decisive arguments for its complete replacement but for its use adapted to the peculiarities of the disease manifestation and of the patients. A "broad" comparison is first made with almost all alternatives studied in the last decade, and then a meta-regression study is performed to compare and predict the effect size induced by viscosupplementation therapy and its main challenger of clinical interest, the platelet-rich plasma treatment. If they are computerized, the developed models can represent tools for clinicians in determining the appropriateness of the option or not for viscosupplementation in a manner adapted to the pain felt by the patients, to their age, or to other clinical circumstances. The models were generated using algorithms implemented in the R language and assembled in different R packages. All primary data and necessary R scripts are provided in accordance with the philosophy of reproducible research. Finally, we adhere in a documented way to the opinion that HA-based products, currently under circumspection, are still clinically useful.

Collagen-Mesenchymal Stem Cell Microspheres Embedded in Hyaluronic Acid Solutions as Biphasic Stem Niche Delivery Systems for Pulmonary Differentiation

Cell therapy has the potential to become a feasible solution for several diseases, such as those related to the lungs and airways, considering the more beneficial intratracheal administration route. However, in lung diseases, an impaired pulmonary extracellular matrix (ECM) precludes injury resolution with a faulty engraftment of mesenchymal stem cells (MSCs) at the lung level. Furthermore, a shielding strategy to avoid cell damage as well as cell loss due to backflow through the injection path is required. Here, an approach to deliver cells encapsulated in a biomimetic stem niche is used, in which the interplay between cells and physiological lung ECM constituents, such as collagen and hyaluronic acid (HA), can occur. To this aim, a biphasic delivery system based on MSCs encapsulated in collagen microspheres (mCOLLs) without chemical modification and embedded in an injectable HA solution has been developed. Such biphasic delivery systems can both increase the mucoadhesive properties at the site of interest and improve cell viability and pulmonary differentiation. Rheological results showed a similar viscosity at high shear rates compared to the MSC suspension used in intratracheal administration. The size of the mCOLLs can be controlled, resulting in a lower value of 200 μm, suitable for delivery in alveolar sacs. Biological results showed that mCOLLs maintained good cell viability, and when they were suspended in lung medium implemented with low molecular weight HA, the differentiation ability of the MSCs was further enhanced compared to their differentiation ability in only lung medium. Overall, the results showed that this strategy has the potential to improve the delivery and viability of MSCs, along with their differentiation ability, in the pulmonary lineage.

Design of Carboxymethylcellulose/Poloxamer-Based Bioformulation Embedding Trichoderma afroharzianum for Agricultural Applications

Microbial biological control agents are believed to be a potential alternative to classical fertilizers to increase the sustainability of agriculture. In this work, the formulation of Trichoderma afroharzianum T22 (T22) spores with carboxymethyl cellulose (CMC) and Pluronic F-127 (PF-127) solutions was investigated. Rheological and microscopical analysis were performed on T22-based systems at three different CMC/PF-127 concentrations, showing that polymer aggregates tend to surround T22 spores, without viscosity, and the viscoelastic properties of the formulations were affected. Contact angle measurements showed the ability of PF-127 to increase the wettability of the systems, and the effect of the formulations on the viability of the spores was evaluated. The viability of the spores was higher over 21 days in all the formulations, compared to the control in water, at 4 and 25 °C. Finally, the effectiveness of the formulations on sweet basil was estimated by greenhouse tests. The results revealed a beneficial effect of the CMC/PF-127 mixture, but none on the formulation with T22. The data show the potential of CMC/PF-127 mixtures for the future design of microorganism-based formulations.

Biomimetic zwitterionic copolymerized chitosan as an articular lubricant

Restoration of the lubrication functions of articular cartilage is an effective treatment to alleviate the progression of osteoarthritis (OA). Herein, we fabricated chitosan-block-poly(sulfobetaine methacrylate) (CS-b-pSBMA) copolymer via a free radical polymerization of sulfobetaine methacrylate onto activated chitosan segment, structurally mimicking the lubricating biomolecules on cartilage. The successful copolymerization of CS-b-pSBMA was verified by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and 1H nuclear magnetic resonance. Friction test confirmed that the CS-b-pSBMA copolymer could achieve an excellent lubrication effect on artificial joint materials such as Ti6Al4V alloy with a coefficient of friction as low as 0.008, and on OA-simulated cartilage, better than the conventional lubricant hyaluronic acid, and the adsorption effect of lubricant on cartilage surface was proved by a fluorescence labeling experiment. In addition, CS-b-pSBMA lubricant possessed an outstanding stability, which can withstand enzymatic degradation and even a long-term storage up to 4 weeks. In vitro studies showed that CS-b-pSBMA lubricant had a favorable antibacterial activity and good biocompatibility. In vivo studies confirmed that the CS-b-pSBMA lubricant was stable and could alleviate the degradation process of cartilage in OA mice. This biomimetic lubricant is a promising articular joint lubricant for the treatment of OA and cartilage restoration.

A Covalently Cross-Linked Hyaluronic Acid/Carboxymethyl Cellulose Composite Hydrogel as a Potential Filler for Soft Tissue Augmentation

The use of fillers for soft tissue augmentation is an approach to restore the structure in surgically or traumatically created tissue voids. Hyaluronic acid (HA), is one of the main components of the extracellular matrix, and it is widely employed in the design of materials with features similar to human tissues. HA-based fillers already find extensive use in soft tissue applications, but are burdened with inherent drawbacks, such as poor thermal stability. A well-known strategy to improve the HA properties is to reticulate it with 1,4-Butanediol diglycidyl ether (BDDE). The aim of this work was to improve the design of HA hydrogels as fillers, by developing a crosslinking HA method with carboxymethyl cellulose (CMC) by means of BDDE. CMC is a water soluble cellulose ether, whose insertion into the hydrogel can lead to increased thermal stability. HA/CMC hydrogels at different ratios were prepared, and their rheological properties and thermal stability were investigated. The hydrogel with an HA/CMC ratio of 1/1 resulted in the highest values of viscoelastic moduli before and after thermal treatment. The morphology of the hydrogel was examined via SEM. Biocompatibility response, performed with the Alamar blue assay on fibroblast cells, showed a safety percentage of around 90% until 72 h.

Viscoelasticity of Liposomal Dispersions

Janus-faced viscoelastic gelling agents-possessing both elastic and viscous characteristics-provide materials with unique features including strengthening ability under stress and a liquid-like character with lower viscosities under relaxed conditions. The mentioned multifunctional character is manifested in several body fluids such as human tears, synovial liquids, skin tissues and mucins, endowing the fluids with a special physical resistance property that can be analyzed by dynamic oscillatory rheology. Therefore, during the development of pharmaceutical or cosmetical formulations-with the intention of mimicking the physiological conditions-rheological studies on viscoelasticity are strongly recommended and the selection of viscoelastic preparations is highlighted. In our study, we aimed to determine the viscoelasticity of various liposomal dispersions. We intended to evaluate the impact of lipid concentration, the presence of cholesterol or 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and the gelling agents polyvinyl alcohol (PVA) and hydroxyethylcellulose (HEC) on the viscoelasticity of vesicular systems. Furthermore, the effect of two model drugs (phenyl salicylate and caffeine) on the viscoelastic behavior of liposomal systems was studied. Based on our measurements, the oscillation rheological properties of the liposomal formulations were influenced both by the composition and the lamellarity/size of the lipid vesicles.

Fermentation-Derived Albumin-Based Hydrogels for Tissue Adhesion Applications

Currently, most of the clinically available surgical glues and sealants lack elasticity, good adhesion and biocompatibility properties. Hydrogels as tissue adhesives have received extensive attention for their tissue-mimicking features. Here, a novel surgical glue hydrogel based on a fermentation-derived human albumin (rAlb) and biocompatible crosslinker for tissue-sealant applications has been developed. In order to reduce the risks of viral transmission diseases and an immune response, Animal-Free Recombinant Human Albumin from the saccharomyces yeast strain was used. A more biocompatible crosslinking agent, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC), was used and compared with glutaraldehyde (GA). The design of crosslinked albumin-based adhesive gels was optimized by varying the albumin concentration, the mass ratio between albumin and the crosslinking agent as well as the crosslinker type. Tissue sealants were characterized in terms of mechanical (tensile and shear), adhesive and in vitro biocompatibility properties. The results indicated that the mechanical and adhesive properties improved as the albumin concentration increased and the mass ratio between albumin and crosslinker decreased. Moreover, the EDC-crosslinked albumin gels have better biocompatibility properties than GA-crosslinked glues.

Effect of Hyaluronic Acid and Mesenchymal Stem Cells Secretome Combination in Promoting Alveolar Regeneration

Pharmacological therapies in lung diseases are nowadays useful in reducing the symptomatology of lung injury. However, they have not yet been translated to effective treatment options able to restore the lung tissue damage. Cell-therapy based on Mesenchymal Stem Cells (MSCs) is an attractive, as well as new therapeutic approach, although some limitations can be ascribed for therapeutic use, such as tumorigenicity and immune rejection. However, MSCs have the capacity to secrete multiple paracrine factors, namely secretome, capable of regulating endothelial and epithelial permeability, decrease inflammation, enhancing tissue repair, and inhibiting bacterial growth. Furthermore, Hyaluronic acid (HA) has been demonstrated to have particularly efficacy in promoting the differentiation of MSCs in Alveolar type II (ATII) cells. In this frame, the combination of HA and secretome to achieve the lung tissue regeneration has been investigated for the first time in this work. Overall results showed how the combination of HA (low and medium molecular weight HA) plus secretome could enhance MSCs differentiation in ATII cells (SPC marker expression of about 5 ng/mL) compared to the only HA or secretome solutions alone (SPC about 3 ng/mL, respectively). Likewise, cell viability and cell rate of migration were reported to be improved for HA and secretome blends, indicating an interesting potentiality of such systems for lung tissue repair. Moreover, an anti-inflammatory profile has been revealed when dealing with HA and secretome mixtures. Therefore, these promising results can allow important advance in the accomplishment of the future therapeutic approach in respiratory diseases, up to date still missing.