In vitro and in vivo biocompatibility and inflammation response of methacrylated and maleated hyaluronic acid for wound healing

Advances in 3D Culture Models to Study Exosomes in Triple-Negative Breast Cancer

Breast cancer, a leading cause of cancer-related deaths globally, exhibits distinct subtypes with varying pathological, genetic, and clinical characteristics. Despite advancements in breast cancer treatments, its histological and molecular heterogeneity pose a significant clinical challenge. Triple-negative breast cancer (TNBC), a highly aggressive subtype lacking targeted therapeutics, adds to the complexity of breast cancer treatment. Recent years have witnessed the development of advanced 3D culture technologies, such as organoids and spheroids, providing more representative models of healthy human tissue and various malignancies. These structures, resembling organs in structure and function, are generated from stem cells or organ-specific progenitor cells via self-organizing processes. Notably, 3D culture systems bridge the gap between 2D cultures and in vivo studies, offering a more accurate representation of in vivo tumors' characteristics. Exosomes, small nano-sized molecules secreted by breast cancer and stromal/cancer-associated fibroblast cells, have garnered significant attention. They play a crucial role in cell-to-cell communication, influencing tumor progression, invasion, and metastasis. The 3D culture environment enhances exosome efficiency compared to traditional 2D cultures, impacting the transfer of specific cargoes and therapeutic effects. Furthermore, 3D exosomes have shown promise in improving therapeutic outcomes, acting as potential vehicles for cancer treatment administration. Studies have demonstrated their role in pro-angiogenesis and their innate therapeutic potential in mimicking cellular therapies without side effects. The 3D exosome model holds potential for addressing challenges associated with drug resistance, offering insights into the mechanisms underlying multidrug resistance and serving as a platform for drug screening. This review seeks to emphasize the crucial role of 3D culture systems in studying breast cancer, especially in understanding the involvement of exosomes in cancer pathology.

Antibacterial and bioactive multilayer electrospun wound dressings based on hyaluronic acid and lactose-modified chitosan

Antibacterial multilayer electrospun matrices based on hyaluronic acid (HA) and a lactose-modified chitosan (CTL) were synthetized (i) by combining electrospun polycaprolactone (PCL) and polysaccharidic matrices in a bilayer device and (ii) by sequentially coating the PCL mat with CTL and HA. In both cases, the antibacterial activity was provided by loading rifampicin within the PCL support. All matrices disclosed suitable morphology and physicochemical properties to be employed as wound dressings. Indeed, both the bilayer and coated fibers showed an optimal swelling capacity (3426 ± 492 % and 1435 ± 251 % after 7 days, respectively) and water vapor permeability (160 ± 0.78 g/m2h and 170 ± 12 g/m2h at 7 days, respectively). On the other hand, the polysaccharidic dressings were completely wettable in the presence of various types of fluids. Depending on the preparation method, a different release of both polysaccharides and rifampicin was detected, and the immediate polysaccharide dissolution from the bilayer structure impacted the antibiotic release (42 ± 4 % from the bilayer structure against 25 ± 2 % from the coated fibers in 4 h). All the multilayer matrices, regardless of their production strategy and composition, revealed optimal biocompatibility and bioactivity with human dermal fibroblasts, as the released bioactive polysaccharides induced a faster wound closure in the cell monolayer (100 % in 24 h) compared to the controls (78 ± 8 % for untreated cells and 89 ± 5 % for cells treated with PCL alone, after 24 h). The inhibitory and bactericidal effects of the rifampicin loaded matrices were assessed on S. aureus, S. epidermidis, E. coli, and P. aeruginosa. The antibacterial matrices were found to be highly effective except for E. coli, which was more resistant even at higher amounts of rifampicin, with a bacterial concentration of 6.4 ± 0.4 log CFU/mL and 6.8 ± 0.3 log CFU/mL after 4 h in the presence of the rifampicin-loaded bilayer and coated matrices, respectively.

Material matters: exploring the interplay between natural biomaterials and host immune system

Biomaterials are widely used for various medical purposes, for instance, implants, tissue engineering, medical devices, and drug delivery systems. Natural biomaterials can be obtained from proteins, carbohydrates, and cell-specific sources. However, when these biomaterials are introduced into the body, they trigger an immune response which may lead to rejection and failure of the implanted device or tissue. The immune system recognizes natural biomaterials as foreign substances and triggers the activation of several immune cells, for instance, macrophages, dendritic cells, and T cells. These cells release pro-inflammatory cytokines and chemokines, which recruit other immune cells to the implantation site. The activation of the immune system can lead to an inflammatory response, which can be beneficial or detrimental, depending on the type of natural biomaterial and the extent of the immune response. These biomaterials can also influence the immune response by modulating the behavior of immune cells. For example, biomaterials with specific surface properties, such as charge and hydrophobicity, can affect the activation and differentiation of immune cells. Additionally, biomaterials can be engineered to release immunomodulatory factors, such as anti-inflammatory cytokines, to promote a tolerogenic immune response. In conclusion, the interaction between biomaterials and the body's immune system is an intricate procedure with potential consequences for the effectiveness of therapeutics and medical devices. A better understanding of this interplay can help to design biomaterials that promote favorable immune responses and minimize adverse reactions.

Advances in the Physico-Chemical, Antimicrobial and Angiogenic Properties of Graphene-Oxide/Cellulose Nanocomposites for Wound Healing

Graphene oxide (GO) and its reduced form (rGO) have recently attracted a fascinating interest due to their physico-chemical properties, which have opened up new and interesting opportunities in a wide range of biomedical applications, such as wound healing. It is worth noting that GO and rGO may offer a convenient access to its ready dispersion within various polymeric matrices (such as cellulose and its derivative forms), owing to their large surface area, based on a carbon skeleton with many functional groups (i.e., hydroxyl, carboxyl, epoxy bridge, and carbonyl moieties). This results in new synergic properties due to the presence of both components (GO or rGO and polymers), acting at different length-scales. Furthermore, they have shown efficient antimicrobial and angiogenic properties, mostly related to the intracellular formation of reactive oxygen species (ROS), which are advantageous in wound care management. For this reason, GO or rGO integration in cellulose-based matrixes have allowed for designing highly advanced multifunctional hybrid nanocomposites with tailored properties. The current review aims to discuss a potential relationship between structural and physico-chemical properties (i.e., size, edge density, surface chemistry, hydrophilicity) of the nanocomposites with antimicrobials and angiogenic mechanisms that synergically influence the wound healing phenomenon, by paying particular attention to recent findings of GO or rGO/cellulose nanocomposites. Accordingly, after providing a general overview of cellulose and its derivatives, the production methods used for GO and rGO synthesis, the mechanisms that guide antimicrobial and angiogenic processes of tissue repair, as well as the most recent and remarkable outcomes on GO/cellulose scaffolds in wound healing applications, will be presented.

Hyaluronic Acid in Biomedical Fields: New Trends from Chemistry to Biomaterial Applications

The aim of this review is to give an updated perspective about the methods for chemical modifications of hyaluronic acid (HA) toward the development of new applications in medical devices and material engineering. After a brief introduction on chemical, structural and biological features of this important natural polysaccharide, the most important methods for chemical and physical modifications are disclosed, discussing both on the formation of new covalent bonds and the interaction with other natural polysaccharides. These strategies are of paramount importance in the production of new medical devices and materials with improved properties. In particular, the use of HA in the development of new materials by means of additive manufacturing techniques as electro fluid dynamics, i.e., electrospinning for micro to nanofibres, and three-dimensional bioprinting is also discussed.

Eumelanin from the Black Soldier Fly as Sustainable Biomaterial: Characterisation and Functional Benefits in Tissue-Engineered Composite Scaffolds

An optimized extraction protocol for eumelanins from black soldier flies (BSF-Eumel) allows an in-depth study of natural eumelanin pigments, which are a valuable tool for the design and fabrication of sustainable scaffolds. Here, water-soluble BSF-Eumel sub-micrometer colloidal particles were used as bioactive signals for developing a composite biomaterial ink for scaffold preparation. For this purpose, BSF-Eumel was characterized both chemically and morphologically; moreover, biological studies were carried out to investigate the dose-dependent cell viability and its influence on human mesenchymal stem cells (hMSCs), with the aim of validating suitable protocols and to find an optimal working concentration for eumelanin-based scaffold preparation. As proof of concept, 3D printed scaffolds based on methacrylated hyaluronic acid (MEHA) and BSF-Eumel were successfully produced. The scaffolds with and without BSF-Eumel were characterized in terms of their physico-chemical, mechanical and biological behaviours. The results showed that MEHA/BSF-Eumel scaffolds had similar storage modulus values to MEHA scaffolds. In terms of swelling ratio and stability, these scaffolds were able to retain their structure without significant changes over 21 days. Biological investigations demonstrated the ability of the bioactivated scaffolds to support the adhesion, proliferation and osteogenic differentiation of human mesenchymal stem cells.

Multifunctional dual cross-linked poly (vinyl alcohol)/methacrylate hyaluronic acid/chitooligosaccharide-sinapic acid wound dressing hydrogel

Wound dressing hydrogel with multifunctional properties, including antioxidant and antimicrobial properties and appropriate mechanical, biological, and physical properties is of great interest in wound healing application and it is still a challenge. In the present study, chitooligosaccharides (COS)/ sinapic acid (SA) conjugate (COS-SA) was synthesized using H₂O₂-induced grafting polymerization, and photo cross-linkable hyaluronic acid was synthesized using methacrilation (HAMA). The synthesis of COS-SA and HAMA was confirmed by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, ultraviolet spectroscopy, and polyphenol assay. Subsequently, we developed duel cross-linked polyvinyl alcohol (PVA)/HAMA composite hydrogel encapsulated with COS-SA as an antioxidant and antimicrobial dressing for full-thickness wound healing application. The chemical, physical, mechanical, antioxidant, antimicrobial, in vitro biocompatibility, and in vivo wound healing properties of hydrogels were subsequently investigated. The results showed that the fabricated composite hydrogel had a uniform porous architecture, excellent fluid absorbability, and appropriate mechanical stability. The introduction of COSs-SA conjugate remarkably enhanced the in vitro biocompatibility, antioxidant, and antimicrobial properties of the hydrogel, leading to the significant promotion of in vivo full-thickness wound closure, re-epithelization, granulation tissue formation, and collagen deposition indicating that COSs-SA incorporated PVA/HAMA hydrogel wound dressing has significant potential for chronic wound healing application.

Three-Dimensional Bioprinting for Cartilage Tissue Engineering: Insights into Naturally-Derived Bioinks from Land and Marine Sources

In regenerative medicine and tissue engineering, the possibility to: (I) customize the shape and size of scaffolds, (II) develop highly mimicked tissues with a precise digital control, (III) manufacture complex structures and (IV) reduce the wastes related to the production process, are the main advantages of additive manufacturing technologies such as three-dimensional (3D) bioprinting. Specifically, this technique, which uses suitable hydrogel-based bioinks, enriched with cells and/or growth factors, has received significant consideration, especially in cartilage tissue engineering (CTE). In this field of interest, it may allow mimicking the complex native zonal hyaline cartilage organization by further enhancing its biological cues. However, there are still some limitations that need to be overcome before 3D bioprinting may be globally used for scaffolds’ development and their clinical translation. One of them is represented by the poor availability of appropriate, biocompatible and eco-friendly biomaterials, which should present a series of specific requirements to be used and transformed into a proper bioink for CTE. In this scenario, considering that, nowadays, the environmental decline is of the highest concerns worldwide, exploring naturally-derived hydrogels has attracted outstanding attention throughout the scientific community. For this reason, a comprehensive review of the naturally-derived hydrogels, commonly employed as bioinks in CTE, was carried out. In particular, the current state of art regarding eco-friendly and natural bioinks’ development for CTE was explored. Overall, this paper gives an overview of 3D bioprinting for CTE to guide future research towards the development of more reliable, customized, eco-friendly and innovative strategies for CTE.

Musculoskeletal tissues-on-a-chip: role of natural polymers in reproducing tissue-specific microenvironments

Over the past years, 3D in vitro models have been widely employed in the regenerative medicine field. Among them, organ-on-a-chip technology has the potential to elucidate cellular mechanism exploiting multichannel microfluidic devices to establish 3D co-culture systems that offer control over the cellular, physico-chemical and biochemical microenvironments. To deliver the most relevant cues to cells, it is of paramount importance to select the most appropriate matrix for mimicking the extracellular matrix of the native tissue. Natural polymers-based hydrogels are the elected candidates for reproducing tissue-specific microenvironments in musculoskeletal tissue-on-a-chip models owning to their interesting and peculiar physico-chemical, mechanical and biological properties. Despite these advantages, there is still a gap between the biomaterials complexity in conventional tissue engineering and the application of these biomaterials in 3D in vitro microfluidic models. In this review, the aim is to suggest the adoption of more suitable biomaterials, alternative crosslinking strategies and tissue engineered-inspired approaches in organ-on-a-chip to better mimic the complexity of physiological musculoskeletal tissues. Accordingly, after giving an overview of the musculoskeletal tissue compositions, the properties of the main natural polymers employed in microfluidic systems are investigated, together with the main musculoskeletal tissues-on-a-chip devices.

Injectable Mesoporous Bioactive Nanoparticles Regenerate Bone Tissue under Osteoporosis Conditions

The osteogenic capability of mesoporous bioactive nanoparticles (MBNPs) in the SiO₂-CaO system has been assessed in vivo using an osteoporotic rabbit model. MBNPs have been prepared using a double template method, resulting in spherical nanoparticles with a porous core-shell structure that has a high surface area and the ability to incorporate the anti-osteoporotic drug ipriflavone. In vitro expression of the pro-inflammatory genes NF-κB1, IL-6, TNF-α, P38 and NOS2 in RAW-264.7 macrophages, indicates that these nanoparticles do not show adverse inflammatory effects. An injectable system has been prepared by suspending MBNPs in a hyaluronic acid-based hydrogel, which has been injected intraosseously into cavitary bone defects in osteoporotic rabbits. The histological analyses evidenced that MBNPs promote bone regeneration with a moderate inflammatory response. The incorporation of ipriflavone into these nanoparticles resulted in a higher presence of osteoblasts and enhanced angiogenesis at the defect site, but without showing significant differences in terms of new bone formation. STATEMENT OF SIGNIFICANCE: Mesoporous bioactive glass nanoparticles have emerged as one of the most interesting materials in the field of bone regeneration therapies. For the first time, injectable mesoporous bioactive nanoparticles have been tested in vivo using an osteoporotic animal model. Our findings evidence that MBG nanoparticles can be loaded with an antiosteoporotic drug, ipriflavone, and incorporated in hyaluronic acid to make up an injectable hydrogel. The incorporation of MBG nanoparticles promotes bone regeneration even under osteoporotic conditions, whereas the presence of IP enhances angiogenesis as well as the presence of osteoblast cells lining in the newly formed bone. The injectable device presented in this work opens new possibilities for the intraosseous treatment of osteoporotic bone using minimally invasive surgery.

Exosomes of mesenchymal stem cells delivered from methacrylated hyaluronic acid patch improve the regenerative properties of endothelial and dermal cells

Wound care management urgently needs the development of innovative smart wound dressings. The complexity of the wound often requires the use of personalized medication and the advent of three-dimensional (3D) bioprinting fits strongly with this need. In this view, in the present work a methacrylated hyaluronic acid (MeHA) bioink was tested for the fabrication of advanced smart patches as a delivery system of exosomes derived from human mesenchymal stem cells (hMSC-EXOs) suitable for wound healing purposes. MeHA patches were realized by 3D bioprinting technique and they were loaded with hMSC-EXOs. The 3D printed MeHA patches revealed improved mechanical performance, appropriate swelling ratio, extended degradation time, and suitable biocompatibility. Furthermore, MeHA patches loaded with hMSC-EXOs improved the proliferation, migration, angiogenic ability, and expression of specific markers related to wound healing process in human fibroblasts and human endothelial cells.

Marine and Agro-Industrial By-Products Valorization Intended for Topical Formulations in Wound Healing Applications

Over the past years, research attention has been focusing more on waste-derived, naturally derived, and renewable materials, in the view of a more sustainable economy. In this work, different topical formulations were obtained from the valorization of marine and agro-industrial by-products and the use of Carbopol 940 as gelling agent. In particular, the combination of extracts obtained from the marine snail, Rapanosa venosa, with Cladophora vagabunda and grape pomace extracts, was investigated for wound healing purposes. Rapana venosa has demonstrated wound healing properties and antioxidant activity. Similarly, grape pomace extracts have been shown to accelerate the healing process. However, their synergic use has not been explored yet. To this aim, four different formulations were produced. Three formulations differed for the presence of a different extract of Rapana venosa: marine collagen, marine gelatin, and collagen hydrolysate, while another formulation used mammalian gelatin as further control. Physico-chemical properties of the extracts as well as of the formulations were analyzed. Furthermore, thermal stability was evaluated by thermogravimetric analysis. Antioxidant capacity and biological behavior, in terms of cytocompatibility, wound healing, and antimicrobial potential, were assessed. The results highlighted for all the formulations (i) a good conservation and thermal stability in time, (ii) a neutralizing activity against free radicals, (iii) and high degree of cytocompatibility and tissue regeneration potential. In particular, collagen, gelatin, and collagen hydrolysate obtained from the Rapana venosa marine snail represent an important, valuable alternative to mammalian products.

Advances in Modified Hyaluronic Acid-Based Hydrogels for Skin Wound Healing

Hyaluronic acid (HA) is a natural linear anionic polysaccharide with many unique characteristics such as excellent biocompatibility and biodegradability, native biofunctionality, hydrophilicity, and non-immunoreactivity. HA plays crucial roles in numerous...