Progress in the Use of Hydrogels for Antioxidant Delivery in Skin Wounds.

The skin is the largest organ of the body, and it acts as a protective barrier against external factors. Chronic wounds affect millions of people worldwide and are associated with significant morbidity and reduced quality of life. One of the main factors involved in delayed wound healing is oxidative injury, which is triggered by the overproduction of reactive oxygen species. Oxidative stress has been implicated in the pathogenesis of chronic wounds, where it is known to impair wound healing by causing damage to cellular components, delaying the inflammatory phase of healing, and inhibiting the formation of new blood vessels. Thereby, the treatment of chronic wounds requires a multidisciplinary approach that addresses the underlying causes of the wound, provides optimal wound care, and promotes wound healing. Among the promising approaches to taking care of chronic wounds, antioxidants are gaining interest since they offer multiple benefits related to skin health. Therefore, in this review, we will highlight the latest advances in the use of natural polymers with antioxidants to generate tissue regeneration microenvironments for skin wound healing.

4D Printing: The Development of Responsive Materials Using 3D-Printing Technology.

Additive manufacturing, widely known as 3D printing, has revolutionized the production of biomaterials. While conventional 3D-printed structures are perceived as static, 4D printing introduces the ability to fabricate materials capable of self-transforming their configuration or function over time in response to external stimuli such as temperature, light, or electric field. This transformative technology has garnered significant attention in the field of biomedical engineering due to its potential to address limitations associated with traditional therapies. Here, we delve into an in-depth review of 4D-printing systems, exploring their diverse biomedical applications and meticulously evaluating their advantages and disadvantages. We emphasize the novelty of this review paper by highlighting the latest advancements and emerging trends in 4D-printing technology, particularly in the context of biomedical applications.

Development and Validation of a Simple, Fast, and Accessible HPLC-UV Method for Cannabinoids Determination in Cannabis sativa L. Extracts and Medicinal Oils.

INTRODUCTION: Cannabis sativa L. is a well-recognized medicinal plant. Cannabis regulations in Argentina are insufficient to solve the problem of patient access to full-spectrum cannabis-based products. So, the market of artisanal products with unknown quality and dosage of cannabinoids is increasing, and so is the local demand and need for analyzing these products. However, much of the latest validated methodologies for cannabinoid quantification include expensive instrumentation that is not always available in laboratories of health institutions in Argentina. METHODS: The aim of this work was to develop and validate a simple and rapid HPLC-UV method for the identification and quantification of principal cannabinoids in cannabis resins, inflorescences, and medicinal oils using standard HPLC equipment. The cannabinoids selected for validation were cannabidiol acid (CBDA), cannabigerol (CBG), cannabidiol (CBD), cannabinol (CBN), delta-9-tetrahydrocannabinol (Δ9-THC), cannabichromene (CBC), and tetrahydrocannabinol acid (THCA). A method for the simultaneous identification and quantification of these 7 main cannabinoids was developed and then validated. Some data parameters were comparable to other reports with more sophisticated analytical instruments for the analysis of cannabis. The assessed limits of detection and the limits of quantitation ranged from 0.9 to 3.66 µg/mL and 2.78 to 11.09 µg/mL, respectively. The concentration-response relationship of the method indicated a linear relationship between the concentration and peak area with R2 values of > 0.99 for all 7 cannabinoids. RESULTS: The relative standard deviation (RSD%) varied from 2.34 to 4.82 for intraday repeatability and from 1.16 to 3.15 for interday repeatability. The percentage of recovery values was between 94 to 115% (resins) and 80 to 103% (inflorescence extract). The cannabis industry is growing rapidly, and there is a need for reliable testing methods to ensure the safety and efficacy of cannabis products. In addition, current methods for cannabinoid analysis are often time-consuming and expensive, while the HPLC-UV method herein reported is a simple, rapid, accurate, and cost-effective alternative for the analysis of cannabinoids in cannabis resins, inflorescences, and medicinal oils. CONCLUSION: This method will be proposed to be included in the Cannabis sativa L. monograph of the Argentine Pharmacopoeia.

Nanosilica size-dependent toxicity in Ceriodaphnia reticulata (Cladocera).

Silica nanoparticles (SiNP) are the most produced nanomaterials due to their variety of applications. When released to environments, surface water bodies are their main final sink. SiNP toxicity is still inconclusive and may vary according to particle properties such as their size. We analyzed the size-related effects of SiNP (22 and 244 nm) on mortality, life history traits, and oxidative stress in the cladoceran Ceriodaphnia reticulata. The smaller SiNP (LC5072 h: 105.5 µg/ml) were more lethal than the larger ones (LC5072 h >500 µg/ml). The 22 nm-sized SiNP decreased the number of molts and neonates, increased superoxide dismutase and inhibited glutathione S-transferase activities, while larger SiNP did not exert substantial effects on the organisms at the tested concentrations. In conclusion, SiNP toxicity depended on their size, and this information should be considered for regulatory purposes and to the development of safe-by-design nanoproducts to ultimately guarantee the environment protection.

Entourage Effect and Analytical Chemistry: Chromatography as a Tool in the Analysis of the Secondary Metabolism of Cannabis sativa L.

Cannabis sativa L. has been used as medicine for thousands of years. Since the early identification of tetrahydrocannabinol (THC) in 1960, pharmacological activities were attributed to a group of unique structures named cannabinoids. For decades, research and development were applied to determine different cannabinoids and their medicinal properties. Nowadays there is evidence that the therapeutic benefits of the plant are based on the synergy of cannabinoids and other secondary metabolites such as terpenes and flavonoids. Differences between the medical performance of isolated compounds like cannabidiol (CBD) or THC and full-spectrum plant extracts are notable. Indeed, the superiority of the last one is provoked by the synergy between various different compounds. This improved medicinal effect is called the entourage effect. Chromatography has become the method of choice for the determination of cannabinoids, terpenes, and flavonoids, so it represents an excellent tool for a proper characterization of the plant and plant derived products. The objective of characterization relies not only in analyzing the fingerprint of cannabis, but also to identify different chemotypes for medical purposes. To understand the contributions of each natural product to this "entourage effect", this review presents an in-depth analysis of the utilization of High-performance liquid chromatography (HPLC), Gas chromatography (GC) and other methods for the analysis of phytocomponents of Cannabis sativa L. In this sense, a representative number of examples and advances made in the field together with limitations and future needs are provided. It can be concluded that standardized protocols and quality control policies and procedures are necessary for the comprehensive analysis of cannabis extracts and derivatives.

Green Synthesized Nanomaterials for Safe Technology in Sustainable Agriculture.

Nanotechnology is a new emerging cutting-edge technology in the 21st century and has applications in medical, cosmetics, electronics, energy, food, agriculture, and many sectors. Nanomaterials (NMs) are the main component of nanotechnology. NMs prepared by chemical routes are very hazardous and not safe for life. Therefore, attempts are being made to prepare NMs via different green routes. It is expected that nanotechnology using green synthesized NMs will be safe. At the same time, green synthesized nanomaterials will be cost-effective. In this chapter, the applications of green synthesized NMs in agriculture have been discussed in detail.

Ecotoxicity of nanosilver on cladocerans and the role of algae provision.

Silver nanoparticles (AgNPs) are applied in diverse industries due to their biocide and physicochemical properties; therefore, they can be released into aquatic systems, interact with environmental factors, and ultimately exert adverse effects on the biota. We analyzed AgNPs effects on Ceriodaphnia reticulata (Cladocera) through mortality and life-history traits, considering the influence of food (Tetradesmus obliquus, Chlorophyceae) presence and concentration. C. reticulata was exposed to AgNPs in acute (absence and two algae concentrations plus five AgNPs treatments) and chronic assays (two algae concentrations plus three AgNPs treatments). AgNPs did not affect algae flocculation but increased Ag+ release, being these ions less toxic than AgNPs (as proved by the exposure to AgNO3). A reduction in AgNPs acute toxicity was observed when algae concentration increased. Acute AgNP exposure decreased C. reticulata body size and heart rate. The chronic AgNP exposure reduced C. reticulata molt number, growth, heart rate, and neonate size:number ratio, being these effects mitigated at the highest algae concentration. Increases in relative size and number of neonates were observed in AgNP treatments suggesting energy trade off. The increased Ag+ release with food presence suggests that the AgNP-algae interaction might be responsible of the decreased toxicity. Although algae reduced AgNP toxicity, they still exerted adverse effects on C. reticulata below predicted environmental concentrations. Since algae presence reduces AgNP effects but increases Ag+ release, studies should be continued to provide evidence on their toxicity to other organisms.

Green Synthesis: A Land of Complex Nanostructures.

The green synthesis of nanomaterials is nowadays gaining great attention owing to several beneficial aspects in terms of the low toxicity of reagents and by-products, low damage to the health and the environment, sustainability of energy savings and rational use of natural resources. The intrinsic complexity offered by the biological sources (plants, microorganisms, animal products) and the conditions applied in the synthetic procedures forms various nanomaterials with different sizes, morphologies and surface properties that strongly determine their functionality and applications. A deep understanding of the role of biological components, the mechanism of nanostructure formation and growth, and the effects of green synthesis conditions is of paramount importance to achieving the desired nanomaterial for the required application. In this context, this review aims to provide an overview of the structural and functional complexity of nanomaterials achieved by using green synthesis procedures, with a special focus on the role of biological sources and parameters in controlling the complexity and benefit of nanomaterial applications.

Design of a New 3D Gelatin-Alginate Scaffold Loaded with Cannabis sativa Oil.

There is an increasing medical need for the development of new materials that could replace damaged organs, improve healing of critical wounds or provide the environment required for the formation of a new healthy tissue. The three-dimensional (3D) printing approach has emerged to overcome several of the major deficiencies of tissue engineering. The use of Cannabis sativa as a therapy for some diseases has spread throughout the world thanks to its benefits for patients. In this work, we developed a bioink made with gelatin and alginate that was able to be printed using an extrusion 3D bioprinter. The scaffolds obtained were lyophilized, characterized and the swelling was assessed. In addition, the scaffolds were loaded with Cannabis sativa oil extract. The presence of the extract provided antimicrobial and antioxidant activity to the 3D scaffolds. Altogether, our results suggest that the new biocompatible material printed with 3D technology and with the addition of Cannabis sativa oil could become an attractive alternative to common treatments of soft-tissue infections and wound repair.

Progress in Gelatin as Biomaterial for Tissue Engineering.

Tissue engineering has become a medical alternative in this society with an ever-increasing lifespan. Advances in the areas of technology and biomaterials have facilitated the use of engineered constructs for medical issues. This review discusses on-going concerns and the latest developments in a widely employed biomaterial in the field of tissue engineering: gelatin. Emerging techniques including 3D bioprinting and gelatin functionalization have demonstrated better mimicking of native tissue by reinforcing gelatin-based systems, among others. This breakthrough facilitates, on the one hand, the manufacturing process when it comes to practicality and cost-effectiveness, which plays a key role in the transition towards clinical application. On the other hand, it can be concluded that gelatin could be considered as one of the promising biomaterials in future trends, in which the focus might be on the detection and diagnosis of diseases rather than treatment.

Building the Bridge From Aquatic Nanotoxicology to Safety by Design Silver Nanoparticles.

Nanotechnologies have rapidly grown, and they are considered the new industrial revolution. However, the augmented production and wide applications of engineered nanomaterials (ENMs) and nanoparticles (NPs) inevitably lead to environmental exposure with consequences on human and environmental health. Engineered nanomaterial and nanoparticle (ENM/P) effects on humans and the environment are complex and largely depend on the interplay between their peculiar properties such as size, shape, coating, surface charge, and degree of agglomeration or aggregation and those of the receiving media/body. These rebounds on ENM/P safety and newly developed concepts such as the safety by design are gaining importance in the field of sustainable nanotechnologies. This article aims to review the critical characteristics of the ENM/Ps that need to be addressed in the safe by design process to develop ENM/Ps with the ablility to reduce/minimize any potential toxicological risks for living beings associated with their exposure. Specifically, we focused on silver nanoparticles (AgNPs) due to an increasing number of nanoproducts containing AgNPs, as well as an increasing knowledge about these nanomaterials (NMs) and their effects. We review the ecotoxicological effects documented on freshwater and marine species that demonstrate the importance of the relationship between the ENM/P design and their biological outcomes in terms of environmental safety.

The 3D Bioprinted Scaffolds for Wound Healing.

Skin tissue engineering and regeneration aim at repairing defective skin injuries and progress in wound healing. Until now, even though several developments are made in this field, it is still challenging to face the complexity of the tissue with current methods of fabrication. In this review, short, state-of-the-art on developments made in skin tissue engineering using 3D bioprinting as a new tool are described. The current bioprinting methods and a summary of bioink formulations, parameters, and properties are discussed. Finally, a representative number of examples and advances made in the field together with limitations and future needs are provided.

Development of 3D-Printed Collagen Scaffolds with In-Situ Synthesis of Silver Nanoparticles.

UV-irradiation method has grown as an alternative approach to in situ synthetize silver nanoparticles (AgNPs) for avoiding the use of toxic reducing agents. In this work, an antimicrobial material by in situ synthesizing AgNPs within 3D-printed collagen-based scaffolds (Col-Ag) was developed. By modifying the concentration of AgNO3 (0.05 and 0.1 M) and UV irradiation time (2 h, 4 h, and 6 h), the morphology and size of the in situ prepared AgNPs could be controlled. As a result, star-like silver particles of around 23 ± 4 µm and spherical AgNPs of 220 ± 42 nm were obtained for Ag 0.05 M, while for Ag 0.1 M cubic particles from 0.3 to 1.0 µm and round silver precipitates of 3.0 ± 0.4 µm were formed in the surface of the scaffolds at different UV irradiation times. However, inside the material AgNPs of 10-28 nm were obtained. The DSC thermal analysis showed that a higher concentration of Ag stabilizes the 3D-printed collagen-based scaffolds, while a longer UV irradiation interval produces a decrease in the denaturation temperature of collagen. The enzymatic degradation assay also revealed that the in situ formed AgNPs act as stabilizing and reinforcement agent which also improve the swelling capacity of collagen-based material. Finally, antimicrobial activity of Col-Ag was studied, showing high bactericidal efficiency against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. These results showed that the UV irradiation method was really attractive to modulate the size and shape of in situ synthesized AgNPs to develop antimicrobial 3D-printed collagen scaffolds with different thermal, swelling and degradation properties.

Collagen Hydrogels Loaded with Silver Nanoparticles and Cannabis Sativa Oil.

Wounds represent a major healthcare problem especially in hospital-associated infections where multi-drug resistant strains are often involved. Nowadays, biomaterials with therapeutic molecules play an active role in wound healing and infection prevention. In this work, the development of collagen hydrogels loaded with silver nanoparticles and Cannabis sativa oil extract is described. The presence of the silver nanoparticles gives interesting feature to the biomaterial such as improved mechanical properties or resistance to collagenase degradation but most important is the long-lasting antimicrobial effect. Cannabis sativa oil, which is known for its anti-inflammatory and analgesic effects, possesses antioxidant activity and successfully improved the biocompatibility and also enhances the antimicrobial activity of the nanocomposite. Altogether, these results suggest that this novel nanocomposite biomaterial is a promising alternative to common treatments of wound infections and wound healing.

Recent Advances in Micro-Electro-Mechanical Devices for Controlled Drug Release Applications.

In recent years, controlled release of drugs has posed numerous challenges with the aim of optimizing parameters such as the release of the suitable quantity of drugs in the right site at the right time with the least invasiveness and the greatest possible automation. Some of the factors that challenge conventional drug release include long-term treatments, narrow therapeutic windows, complex dosing schedules, combined therapies, individual dosing regimens, and labile active substance administration. In this sense, the emergence of micro-devices that combine mechanical and electrical components, so called micro-electro-mechanical systems (MEMS) can offer solutions to these drawbacks. These devices can be fabricated using biocompatible materials, with great uniformity and reproducibility, similar to integrated circuits. They can be aseptically manufactured and hermetically sealed, while having mobile components that enable physical or analytical functions together with electrical components. In this review we present recent advances in the generation of MEMS drug delivery devices, in which various micro and nanometric structures such as contacts, connections, channels, reservoirs, pumps, valves, needles, and/or membranes can be included in their design and manufacture. Implantable single and multiple reservoir-based and transdermal-based MEMS devices are discussed in terms of fundamental mechanisms, fabrication, performance, and drug release applications.

Silicified collagen materials: Modulation of the in vitro and in vivo response.

Collagen derived materials offer distinct advantages over synthetic polymers, considering their natural inherited biocompatibility and mechanical properties. However, because of the extraction procedure, the latter frequently need to be enhanced through the use of different crosslinking methods. Aldehydes are often used for the stabilization of biomaterials but the introduction of crosslinkers slightly alters the protein's surface reactivity hence calling for new biocompatibility studies. At the same time, silicate modification of natural polymers has gained interest within the biomaterials field for their strengthening potential and ease of manipulation, giving rise to different surfaces and bulk materials. In the present work, collagen gels modified with glutaraldehyde (ColGA) or glutaraldehyde and an aminosilane (ColGASi) were evaluated in vitro and in vivo with the aim to obtain biomaterials for wound dressings. The results obtained were compared to those derived from unmodified collagen matrices (Col). In vitro assays focused on the interaction of the materials with elements present in the human blood whereas in vivo assays evaluated their ability to support cell proliferation and angiogenesis for a period of 30 days in a rodent model. Col gels induced an increase in platelet aggregation while ColGA gels decreased it. On the other hand, ColGASi had no effect on platelet aggregation but induced IL-1ß and nitric oxide platelet secretion. All gels induced lower IL-6 levels in PMN cells cultures when compared to controls. Col and ColGA gels decreased IL-1ß concentration whereas ColGASi induced high expression of TGF-ß in PMN cells. All gels decreased nitric oxide secretion but Col and ColGA gels increased IL-1ß production by monocytes. Definitely, all gels induced an anti and pro-inflammatory profile depending on the cell type with which they interact. In vivo, an increased cellular infiltration was observed along with new blood vessel formation in those matrices containing silicified collagen, while glutaraldehyde fixed collagen induced a foreign body reaction and appeared surrounded by a fibrous capsule after 30 days of subcutaneous implantation. Overall, the results obtained show that the silicification of collagen has advantages not only through the enhancement of its mechanical properties but also through the stimulation of the integration of the material with the surrounding tissue.

Copper-induced cell death and the protective role of glutathione: the implication of impaired protein folding rather than oxidative stress.

Copper (Cu) is a bioelement essential for a myriad of enzymatic reactions, which when present in high concentration leads to cytotoxicity. Whereas Cu toxicity is usually assumed to originate from the metal's ability to enhance lipid peroxidation, the role of oxidative stress has remained uncertain since no antioxidant therapy has ever been effective. Here we show that Cu overload induces cell death independently of the metal's ability to oxidize the intracellular milieu. In fact, cells neither lose control of their thiol homeostasis until briefly before the onset of cell death, nor trigger a consistent antioxidant response. As expected, glutathione (GSH) protects the cell from Cu-mediated cytotoxicity but, surprisingly, fully independent of its reactive thiol. Moreover, the oxidation state of extracellular Cu is irrelevant as cells accumulate the metal as cuprous ions. We provide evidence that cell death is driven by the interaction of cuprous ions with proteins which impairs protein folding and promotes aggregation. Consequently, cells mostly react to Cu by mounting a heat shock response and trying to restore protein homeostasis. The protective role of GSH is based on the binding of cuprous ions, thus preventing the metal interaction with proteins. Due to the high intracellular content of GSH, it is depleted near the Cu entry site, and hence Cu can interact with proteins and cause aggregation and cytotoxicity immediately below the plasma membrane.

Development of pH-responsive biopolymer-silica composites loaded with Larrea divaricata Cav. extract with antioxidant activity.

A detailed study of biomaterials is mandatory to comprehend their feasible biomedical applications in terms of drug delivery and tissue regeneration. Particularly, mucoadhesive biopolymers such as chitosan (chi) and carboxymethylcellulose (CMC) have become interesting biomaterials regards to their biocompatibility and non-toxicity for oral mucosal drug delivery. In this work, pH-responsive biopolymer-silica composites (Chi-SiO2, Chi-CMC-SiO2) were developed. These two types of composites presented a different swelling behavior due to the environmental pH. Moreover, the nanocomposites were loaded with aqueous Larrea divaricata Cav. extract (Ld), a South American plant which presents antioxidant properties suitable for the treatment of gingivoperiodontal diseases. Chi-CMC-SiO2 composites showed the highest incorporation and reached the 100% of extract release in almost 4 days while they preserved their antioxidant properties. In this study, thermal and swelling behavior were pointed out to show the distinct water-composite interaction and therefore to evaluate their mucoadhesivity. Furthermore, a cytotoxicity test with 3T3 fibroblasts was assessed, showing that in both composites the addition of Larrea divaricata Cav. extract increased fibroblast proliferation. Lastly, preliminary in vitro studies were performed with simulated body fluids. Indeed, SEM-EDS analysis indicated that only chi-SiO2 composite may provide an environment for possible biomineralization while the addition of CMC to the composites discouraged calcium accumulation. In conclusion, the development of bioactive composites could promote the regeneration of periodontal tissue damaged throughout periodontal disease and the presence of silica nanoparticles could provide an environment for biomineralization.