Alginate-Based Hydrogels and Scaffolds for Biomedical Applications

Preliminary Evaluation of 3D-Printed Alginate/Gelatin Scaffolds for Protein Fast Release as Suitable Devices for Personalized Medicine

Background/Objectives: Drug-coated balloons (DCBs) are emerging as a promising treatment for peripheral artery disease; however, current technologies lack flexibility in customizing drug release profiles and composition, limiting their therapeutic potential. This study aims to develop a Gelatin (Gel) and Sodium Alginate (Alg) bioink loaded with apolipoprotein A-I (apoA-I) for controlled drug delivery by using additive manufacturing technologies. Methods: We developed and printed via rapid freeze prototyping (RFP) a Gel and Alg bioink loaded with different concentrations of apoA-I. Mechanical properties related to compressional and tensile forces have been studied, as well as the structural stability and active release from the 3D structure of apoA-I (cholesterol efflux assays). The biological behavior of HUVEC cells with and without ApoA-I was assessed by proliferation assay, metabolic activity analysis, and fluorescence imaging. Results: The 3D structures presented breakpoint stress values consistent with the mechanical requirements for integration within a DCB, and the ability to effectively promote cholesterol transport in J774 cells. Moreover, in vitro studies on HUVECs revealed that the scaffolds exhibited no cytotoxic effects, leading to increased ATP levels and enhanced metabolic activity over time, confirming the possibility to obtain RFP-printed Alg/Gel scaffolds able to provide a stable structure capable of controlled apoA-I release. Conclusions: These findings support the potential of Alg/Gel+apoA-I scaffolds as biocompatible drug delivery systems for vascular applications. Their ability to maintain structural integrity while enabling controlled biomolecular release positions them as promising candidates for personalized cardiovascular therapy, facilitating the rapid customization of bioprinted therapeutic platforms.

Advancing Organ-on-a-Chip Systems: The Role of Scaffold Materials and Coatings in Engineering Cell Microenvironment

For organ-on-a-chip (OoC) engineering, the use of biocompatible coatings and materials is not only recommended but essential. Extracellular matrix (ECM) components are commonly used as coatings due to their effects on cell orientation, protein expression, differentiation, and adhesion. Among the most frequently used coatings are collagen, fibronectin, and Matrigel, according to the specific cell type and intended OoC application. Additionally, materials such as polydimethylsiloxane (PDMS), thermoplastics, chitosan, and alginate serve as scaffolding components due to their biomechanical properties and biocompatibility. Here, we discuss some of the most employed coating techniques, including SAMs, dip coating, spin coating, microcontact printing, and 3D bioprinting, each offering advantages and drawbacks. Current challenges comprise enhancing biocompatibility, exploring novel materials, and improving scalability and reproducibility.

Optimizing hydrogel performance composed of Japanese pagoda tree extract loaded-gelatin-sodium alginate-polyethylene oxide for biomedical applications: Influence incorporated calcium-based metal organic frameworks and zinc oxide NPs

Gelatin/sodium alginate/polyethylene oxide hydrogel was synthesized by self-gelation method and utilized to achieve enhanced mechanical strength. Japanese pagoda, tree extracts rich in flavonoids and isoflavonoids was incorporated to enhance tissue repair along with ZnO-NPs to provide the hydrogel with necessary antimicrobial and other desirable biological properties. The inclusion of Ca-BDC MOF enhanced hydrogel matrix by providing more surface area and the presence of calcium ion needed for tissue regeneration. Results revealed that composite hydrogel displayed suitable gelation time and swelling rate that was further improved by incorporating the plant extract, ZnO-NPs, and Ca-BDC MOF. The efficacy of the tested formulations to suppress or stop the growth of multi-drug-resistant human pathogens was assessed using both microbial turbidity and zone of inhibition assays. The optimal hydrogel loaded with (20 % plant extract, 0.25 % ZnO and 0.1 % Ca-BDC MOF) formula have stronger antimicrobial effects against Gram-positive bacteria as well as yeast cells than it did against Gram-negative bacteria. Statistically, this formula has recorded a higher percentage of biofilm inhibition on Bacillus cereus (93.45 ± 2.91 %), and Candida krusei (78.48 ± 6.44 %), followed by Klebsiella pneumoniae (76.93 ± 3.65 %). Composite hydrogel loaded with (Japanese pagoda tree extract, ZnO-NPs, Ca-BDC MOF) could be exploited as promising biocompatible antimicrobial biomaterial for biomedical applications.

Hydrogel promotes bone regeneration through various mechanisms: a review

Large defects in bone tissue due to trauma, tumors, or developmental abnormalities usually require surgical treatment for repair. Numerous studies have shown that current bone repair and regeneration treatments have certain complications and limitations. With the in-depth understanding of bone regeneration mechanisms and biological tissue materials, a variety of materials with desirable physicochemical properties and biological functions have emerged in the field of bone regeneration in recent years. Among them, hydrogels have been widely used in bone regeneration research due to their biocompatibility, unique swelling properties, and ease of fabrication. In this paper, the development and classification of hydrogels were introduced, and the mechanism of hydrogels in promoting bone regeneration was described in detail, including the promotion of bone marrow mesenchymal stem cell differentiation, the promotion of angiogenesis, the enhancement of the activity of bone morphogenetic proteins, and the regulation of the microenvironment of bone regeneration tissues. In addition, the future research direction of hydrogel in bone tissue engineering was discussed.

Protective Effects of Fucoidan on Iodoacetamide-Induced Functional Dyspepsia via Modulation of 5-HT Metabolism and Microbiota

As the major polysaccharide in brown algae, fucoidan possesses broad biological abilities and has been reported to improve gastrointestinal health. Functional dyspepsia, a common non-organic disease, is a complex of symptoms mainly characterized by pathogenesis, such as visceral hypersensitivity, gastric dysmotility, and inflammation. To date, the effects of fucoidan in regulating functional dyspepsia with visceral sensitivity remains unclear. In the current study, iodoacetamide was employed to establish a mouse model of visceral hypersensitivity. Meanwhile, fucoidan was orally administrated for fourteen days. Indicators were conducted to evaluate the potential of fucoidan as the ingredient of complementary and alternative medicine for functional dyspepsia, such as levels of serum hormones, expression of receptors, and gut microbial profile. The results show that oral administration of fucoidan led to significant reductions in the secretion of 5-hydroxytryptamine, cortisol, and corticosterone. Additionally, it decreased the expression of 5-hydroxytryptamine-3 receptors, with regulation of 5-hydroxytryptamine metabolism and improvement of gut microbial imbalance. The above results suggest fucoidan could ameliorate visceral hypersensitivity by modulating 5-HT metabolism and microbiota. The current findings indicate that fucoidan has potential as a biological component in the adjuvant treatment of functional dyspepsia and for its expanded utilization in the food and medical fields.

Naturally derived hydrogels for wound healing

Natural hydrogels have garnered increasing attention due to their natural origins and beneficial roles in wound healing. Hydrogel water-retaining capacity and excellent biocompatibility create an ideal moist environment for wound healing, thereby enhancing cell proliferation and tissue regeneration. For this reason, naturally derived hydrogels formulated from biomaterials such as chitosan, alginate, gelatin, and fibroin are highly promising due to their biodegradability and low immunogenic responses. Recent integrated approaches to utilizing new technologies with bioactive agents have significantly improved the mechanical properties of hydrogels and the controlled release and delivery of active compounds, thereby increasing the efficiency of the treatment processes. Herein, this review highlights the advantages and the challenges of natural hydrogels in wound healing, focusing on their mechanical strength, controlled degradation rates, safety and efficiency validation, and the potential for incorporating advanced technologies such as tissue engineering and gene therapy for utilization in personalized medicine.

Development of Antibacterial Hydrogels Based on Biopolymer Aloe Vera/Gelatin/Sodium Alginate Composited With SM-AgNPs Loaded Curcumin-Nanoliposomes

To address the rising prevalence of bacterial infections and the need for innovative therapeutic solutions, this study has developed a novel antibacterial hydrogel composite composed of Aloe vera, gelatin, sodium alginate, and Sterculia monosperma-silver nanoparticles (SM-AgNPs) loaded curcumin-nanoliposomes (NLPs). The aloe vera/gelatin/sodium alginate hydrogels (AGS) are prepared using different weight ratios of Aloe vera, gelatin, and sodium alginate, aiming to optimize mechanical properties and biocompatibility for biomedical applications. The incorporation of SM-AgNPs and curcumin-loaded NLPs enhanced the hydrogels' antibacterial properties. Characterizations of the hydrogels are performed by using Fourier-transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Additional examinations, such as water absorption analysis, rheology measurements, thermal stability, and injectability, along with pH and temperature responsiveness, are also conducted. The AGS-3 hydrogel formulation, with a 1:5:3 ratio of Aloe vera to gelatin to sodium alginate, exhibited significant performance in all tests, making it suitable for further experiments. Furthermore, antimicrobial activity assays showed that AGS hydrogels containing SM-AgNPs/NLP composites effectively inhibited the growth of both gram-positive Staphylococcus aureus (S.aureus) and gram-negative Escherichia coli (E.coli) bacteria. These results indicate that the SM-AgNPs/NLP-AGS hydrogel is a promising material for biomedical applications including wound healing, infection prevention, and targeted drug delivery.

Hydrogels as drug delivery platforms for orthopedic diseases treatment: A review

The skeletal system serves as a crucial support structure for the human body, any damage or disease to bones can result in prolonged pain, impaired mobility, and other negative outcomes. For the treatment of bone diseases, with the in-depth study of the therapeutic mechanism, various small molecule drugs, cells, cytokines, growth factors, bioactive ions, collectively referred to as "drugs" in this context, are increasingly investigated for their potential application in surgical procedures, defect repair, or treatment of diseased bone regions. However, various challenges, including, low stability, the necessity for precise dosage control, are encountered in the administration of drugs. Consequently, the advancement of drug delivery platforms is crucial to safeguard drug efficacy and address the requirement for dosage regulation. Given the attributes of current drug delivery platforms, hydrogels exhibit favorable biocompatibility and offer the ability to easily regulate drug loading and release. As a carrier with diverse properties, abundant varieties, optimal performance, hydrogels present a promising solution in drug delivery. This paper aims to analyze the potential of hydrogel as a delivery platform for treating orthopedics diseases by reviewing the characteristics of hydrogel delivery systems, mechanisms of drug binding, current research findings, and projecting future developments in this field.

Injectable alginate/collagen clindamycin hydrogel for treatment of surgical site infections

The current standard treatment for surgical site infections (SSIs) is marked by prolonged courses of antibiotics, which have limitations due to antibiotic resistance, systemic side effects, and poor patient adherence. We developed a novel injectable alginate/collagen clindamycin hydrogel that rapidly solidifies upon injection and allows for initial burst release followed by sustained release to maintain therapeutic levels. The rheological, morphological, and in-vitro release kinetics of the hydrogel were characterized. Furthermore, with an in-vivo murine SSI model incubated with logarithmic growth phase 1 × 105 CFU Staphylococcus aureus, one time treatment with injectable hydrogel containing 8 mg clindamycin successfully treated SSI comparable to a cumulative systemic antibiotic dose of 42 mg clindamycin. In an implant SSI model, two-time treatment with the injectable clindamycin antibiotic (16 mg total) successfully suppressed infection and prevented recalcitrant infection. To date, no group has developed a clindamycin encapsulated injectable alginate/collagen hydrogel for the treatment of infection. This tunable hydrogel may serve as an effective delivery vehicle for clinical applications in treating SSIs compared to conventionally available treatments.

Fabrication of nanoparticle-reinforced composite hydrogel for improved durability, antifouling, and thrombosis-resistance in arteriovenous grafts

Arteriovenous grafts are routinely designed to provide a deliberate connection between an artery and vein in patients during hemodialysis. The commonly used grafts present significant drawbacks such as thrombosis, bacterial infection, and biofouling which prevents their functionality. To endow hydrogels with improved anti-thrombosis, stable antifouling, and strong mechanical strength, a surface-modified nanoparticle-reinforced nanohybrid hydrogel is developed. In brief, zwitterionic sulfobetaine methacrylate (SBMA) is coated on bentonite clay (BC) nanoparticles via a simple method. BC-SBMA nanoparticles were then loaded onto sodium alginate /polyvinyl alcohol hydrogel composite. Calcium chloride (Ca2+) crosslinking is employed to form stable network and optimize polyvinyl alcohol/sodium alginate (PS) hydrogel composite. BC-SBMA particles were dispersed into PS hydrogel and crosslinked to form nanohybrid hydrogel (PS@BC-SBMA). The nanohybrid hydrogel was characterized for its morphological, mechanical, physicochemical, antibacterial, biocompatibility, antifouling, ex-vivo anti-thrombogenic, and in-vivo anti-inflammatory properties. The results revealed that the presence ofBC-SBMA particles boosted the mechanical strength and facilitated biocompatibility. The presence of zwitterionic polymers provided excellent antifouling properties toward blood platelets, unnecessary proteins, and bacterial strains. Hence, the cooperative effects of the nanohybrid hydrogel such as biocompatibility, antifouling, and mechanical properties lead to a desirable candidate for blood-contacting implants.

Recent Advances in Polysaccharide-Based Hydrogels for Tumor Immunotherapy

Immunotherapy has revolutionized cancer treatment and led to a significant increase in patient survival rates and quality of life. However, the effectiveness of current immunotherapies is limited by various factors, including immune evasion mechanisms and serious side effects. Hydrogels are a type of medical material with an ideal biocompatibility, variable structure, flexible synthesis method, and physical properties. Hydrogels have long been recognized and used as a superior choice for various biomedical applications. The fascinating results were derived from both in vitro and in vivo models. The rapid expansion of this area suggests that the principles and uses of functionalized polysaccharides are transformative, motivating researchers to investigate novel polysaccharide-based hydrogels for wider applications. Polysaccharide hydrogels have proven to be a practicable delivery strategy for tumor immunotherapy due to their biocompatibility, biodegradability, and pronounced bioactive characteristics. This study aims to examine in detail the latest developments of polysaccharide hydrogels in tumor immunotherapy, focusing on their design, mechanism of action, and potential therapeutic applications.

Investigation of the Antibacterial Activity of ZnO-Loaded Alginate/Hyaluronic Acid Aerogels for Wound Dressing Applications

The prevalence of bacterial infections in wounds is a significant challenge to successful wound healing. This study investigates the antibacterial effect of hyaluronic acid and alginate aerogel loaded with zinc oxide nanoparticles as a potential dressing for wound healing. The aerogel composite was synthesized via supercritical gel drying and characterized by scanning electron microscope, Fourier transform infrared spectroscopy, and nitrogen porosimetry. The absorptivity of the prepared aerogel was evaluated, as well as the antibacterial activity, which was evaluated against common wound pathogens, including Staphylococcus aureus and Escherichia coli, using the agar diffusion method. The results show the effective antibacterial properties of the prepared hydrogel and aerogel. Furthermore, the results show water absorption ability of 5791 and 1585% for loaded and unloaded aerogels, respectively. The ZnO released from the aerogel exhibited a rapid release followed by a slow and sustained release. These findings highlight the potential of aerogels based on hyaluronic acid and alginate and loaded with zinc oxide nanoparticles as an innovative antibacterial wound dressing material, which is expected to improve wound healing and reduce the risk of bacterial infections.

Advancements in Bone Replacement Techniques-Potential Uses After Maxillary and Mandibular Resections Due to Medication-Related Osteonecrosis of the Jaw (MRONJ)

Maxillofacial bone defects can have a profound impact on both facial function and aesthetics. While various biomaterial scaffolds have shown promise in addressing these challenges, regenerating bone in this region remains complex due to its irregular shape, intricate structure, and differing cellular origins compared to other bones in the human body. Moreover, the significant and variable mechanical loads placed on the maxillofacial bones add further complexity, especially in cases of difficult-to-treat medical conditions. This review provides a brief overview of medication-related osteonecrosis of the jaw (MRONJ), highlighting the medication-induced adverse reactions and the associated clinical challenges in treating this condition. The purpose of this manuscript is to emphasize the role of biotechnology and tissue engineering technologies in therapy. By using scaffold materials and biofactors in combination with autologous cells, innovative solutions are explored for the repair of damaged facial bones. The ongoing search for effective scaffolds that can address these challenges and improve in vitro bone preparation for subsequent regeneration in the maxillofacial region remains critical. The primary purpose of this review is to spotlight current research trends and novel approaches in this area.

Marine-Derived Polysaccharide Hydrogels as Delivery Platforms for Natural Bioactive Compounds

Marine polysaccharide hydrogels have emerged as an innovative platform for regulating the in vivo release of natural bioactive compounds for medical purposes. These hydrogels, which have exceptional biocompatibility, biodegradability, and high water absorption capacity, create effective matrices for encapsulating different bioactive molecules. In addition, by modifying the physical and chemical properties of marine hydrogels, including cross-linking density, swelling behavior, and response to external stimuli like pH, temperature, or ionic strength, the release profile of encapsulated bioactive compounds is strictly regulated, thus maximizing therapeutic efficacy and minimizing side effects. Finally, by using naturally sourced polysaccharides in hydrogel formulations, sustainability is promoted by reducing dependence on synthetic polymers, meeting the growing demand for eco-friendly materials. This review analyzes the interaction between marine polysaccharide hydrogels and encapsulating compounds and offers examples of how bioactive molecules can be encapsulated, released, and stabilized.

Therapeutic functions of medical implants from various material categories with integrated biomacromolecular systems

Medical implants are designed to replace missing parts or improve body functions and must be capable of providing structural support or therapeutic intervention for a medical condition. Advances in materials science have enabled the development of devices made from metals, polymers, bioceramics, and composites, each with its specific advantages and limitations. This review analyzes the incorporation of biopolymers, proteins, and other biomacromolecules into implants, focusing on their role in biological integration and therapeutic functions. It synthesizes advancements in surface modification, discusses biomacromolecules as carriers for controlled drug release, and explores the application of nanoceramics and composites to improve osseointegration and tissue regeneration. Biomacromolecule systems are capable of interacting with device components and therapeutic agents - such as growth factors (GFs), antibiotics, and nanoceramics - allowing control over substance release. Incorporating therapeutic agents into these systems enables localized treatments for tissue regeneration, osseointegration, post-surgery infection control, and disease and pre-existing conditions. The review highlights these materials' therapeutic advantages and customization opportunities, by covering mechanical and biological perspectives. Developing composites and hybrid drug delivery systems align with recent efforts in interdisciplinary personalized medicine and implant innovations. For instance, a trend was observed for integrating inorganic (especially nanoceramics, e.g., hydroxyapatite) and organic phases in composites for better implant interaction with biological tissues and faster recovery. This article supports understanding how integrating these materials can create more personalized, functional, durable, and biocompatible implant devices.

Simultaneous viscoelasticity and sprayability in antimicrobial acetic acid-alginate fluid gels

Acetic acid is a promising alternative to antibiotics for topical applications, particularly burn wounds, however its site specificity and retention are impaired by poor material properties. In this study, acetic acid was investigated as both the gelling agent and antimicrobial active in alginate fluid gels. The formed microstructure was found to be directly dependent on acetic acid concentration, leading to highly tuneable material properties. At clinically relevant concentrations of 2.5-5 % acetic acid, the fluid gels were elastically dominated at rest, with viscosities up to 7 orders of magnitude greater than acetic acid alone. These material properties imparted long term surface retention and microparticle barrier function, not seen with either acetic acid or alginate solutions. Most notably, sprayability was enhanced simultaneously with the increased viscosity and elasticity due to the introduction of a discretised microstructure, leading to a remarkable tenfold increase in spray coverage. Formulation was found not to inhibit antimicrobial activity, despite the less acidic pH, with common burn wound pathogens Staphylococcus aureus and Pseudomonas aeruginosa being equally susceptible to the fluid gels as to acetic acid solutions.

[Preparation of collagen-polysaccharide composite hydrogels and research progress in biomedical applications]

Collagen contains abundant cell binding motifs, which are conducive to adhesion, migration, and differentiation, maintain cell vitality and promote cell proliferation. However, pure collagen hydrogel has some shortcomings such as poor mechanical properties, poor thermal stability and fast degradation. Numerous studies have shown that the properties of collagen can be improved by combining it with natural polysaccharides such as alginate, chitosan, hyaluronic acid and cellulose. In this paper, the research status and biological application fields of four kinds of composite hydrogels, including collagen-alginate composite hydrogels, collagen-chitosan hydrogels, collagen-hyaluronic acid hydrogels and collagen-cellulose hydrogels, were summarized. The common preparation methods of four kinds of composite hydrogels were introduced, and the future development direction of collagen-based composite hydrogels was prospected.

Cannabidiol-Loaded Lipid Nanoparticles Incorporated in Polyvinyl Alcohol and Sodium Alginate Hydrogel Scaffold for Enhancing Cell Migration and Accelerating Wound Healing

Chronic wounds represent a persistent clinical challenge due to prolonged inflammation and impaired tissue repair mechanisms. Cannabidiol (CBD), recognized for its anti-inflammatory and pro-healing properties, shows therapeutic promise in wound care. However, its delivery via lipid nanoparticles (LNPs) remains challenging due to CBD's inherent instability and low bioavailability. This study developed and characterized a novel hydrogel scaffold composed of CBD-loaded LNPs (CBD/LNPs) integrated into a polyvinyl alcohol (PVA) and sodium alginate (SA) matrix, designed to enhance wound repair and mitigate inflammation. The characteristics of the hydrogel scaffold were observed including the degree of swelling and LNPs' release profiles. Furthermore, in the results, CBD/LNPs displayed enhanced stability and reduced cytotoxicity compared to unencapsulated CBD. In vitro assays demonstrated that CBD/LNPs significantly promoted fibroblast migration in gap-closure wound models and reduced intracellular reactive oxygen species, supporting their potential as a biocompatible and efficacious agent for cellular repair and oxidative stress attenuation. In vivo experiments using adult male Wistar rats with aseptic cutaneous wounds revealed that treatment with CBD/LNP-PVA/SA hydrogel scaffold significantly accelerated wound closure relative to blank hydrogel controls, demonstrating a substantial reduction in the wound area over time. Histological analysis confirms notable improvements in skin morphology in wounds treated with CBD/LNP-PVA/SA hydrogel scaffold with evidence of accelerated epithelialization, enhanced collagen deposition, and increased dermal thickness and vascularization. Additionally, skin histology showed a more organized epidermal layer and reduced inflammatory cell infiltration in CBD/LNP-PVA/SA hydrogel scaffold-treated wounds, corresponding to a 35% increase in the wound closure rate by day 28 post-treatment. These findings suggest that CBD/LNP-PVA/SA hydrogel scaffolds facilitate inflammation resolution and structural wound healing through localized, sustained CBD delivery. The dual anti-inflammatory and wound-healing effects position CBD/LNP-PVA/SA hydrogel scaffold as a promising approach for chronic wound management. Future investigations are warranted to elucidate the mechanistic pathways by which CBD modulates the skin architecture and to explore its translational applications in clinical wound care.

Tunable Alginate-Polyvinyl Alcohol Bioinks for 3D Printing in Cartilage Tissue Engineering

This study investigates 3D extrusion bioinks for cartilage tissue engineering by characterizing the physical properties of 3D-printed scaffolds containing varying alginate and polyvinyl alcohol (PVA) concentrations. We systematically investigated the effects of increasing PVA and alginate concentrations on swelling, degradation, and the elastic modulus of printed hydrogels. Swelling decreased significantly with increased PVA concentrations, while degradation rates rose with higher PVA concentrations, underscoring the role of PVA in modulating hydrogel matrix stability. The highest elastic modulus value was achieved with a composite of 5% PVA and 20% alginate, reaching 0.22 MPa, which approaches that of native cartilage. These findings demonstrate that adjusting PVA and alginate concentrations enables the development of bioinks with tailored physical and mechanical properties, supporting their potential use in cartilage tissue engineering and other biomedical applications.

Inhalable multi-stimulus sensitive curcumin-alginate nanogels for scavenging reactive oxygen species and anti-inflammatory co-ordination to alleviate acute lung injury

Acute lung injury (ALI) is one of the most common and extremely critical clinical conditions, which progresses with an inflammatory response and overproduction of reactive oxygen species (ROS), leading to oxidative damage to the lungs. Curcumin (Cur) has great potential in treating ALI due to its excellent antioxidant and anti-inflammatory effects. In this study, Cur and alginate were cross-linked by zinc ions and intermolecular hydrogen bonding to form an inhalable aqueous nanogel system to overcome Cur's low solubility and bioavailability. Cur-alginate (ZA-Cur) nanogels exhibited superior antioxidant properties and down-regulated inflammation-associated factors in vitro with controlled-release behavior under multi-stimulus conditions such as temperature, pH, and ions. Meanwhile, the nanogels system could effectively scavenge cellular ROS to repair oxidative stress damage. In a mice model of ALI, tracheal nebulised inhalation of ZA-Cur nanogels down-regulated the expression of inflammation-related genes such as TNF-α, IL-1β, and IL-6, as well as modulated MDA content and CAT activity to attenuate oxidative stress injury, showing promising lung-protective effects. In conclusion, this work developed inhalable ZA-Cur nanogels to decelerate the progression of lesions in ALI by scavenging intracellular ROS and alleviating inflammation simultaneously, which may be a promising strategy for treating ALI.

Advances in cancer diagnosis and therapy by alginate-based multifunctional hydrogels: A review

The field of oncology has been changed by the application of hydrogels. These 3D polymeric networks have demonstrated significant promise in the treatment of cancer and can boost the efficacy of conventional therapeutics including chemotherapy and immunotherapy. Noteworthy, the development of biocompatible and effective hydrogels has been of interest. In this case, alginate as a biopolymer and carbohydrate polymer has been used to modify or synthesis multifunctional nanoparticles for the treatment of human diseases, especially cancer. Therefore, highlighting the function of alginate in the development of hydrogels in cancer therapy can provide new insights for improving outcome and survival rate of patients. Alginate hydrogels improve the specific and selective delivery of cargo and therefore, they reduce the systemic toxicity of drugs, while they enhance anti-cancer activity. Alginate hydrogels protect the genes against degradation by enzymes and increase blood circulation time. The alginate hydrogels can respond to the specific stimuli in the tumor microenvironment including pH, redox and light to improve the site-specific release of cargo. The nanoparticles can be incorporated in the structure of alginate hydrogels to augment their anti-cancer activity. In addition, alginate hydrogels can accelerate immunotherapy and phototherapy through delivery of immunomodulators and photosensitizers, respectively.

Sodium alginate/carboxymethylcellulose gel formulations containing Capparis sepieria plant extract for wound healing

Aim: Using appropriate wound dressings is crucial when treating burn wounds to promote accelerated healing.Materials & methods: Sodium alginate (SA)-based gels containing Carboxymethyl cellulose (CMC) and Pluronic F127 were prepared. The formulations. SA/CMC/Carbopol and SA/CMC/PluronicF127 were loaded with aqueous root extract of Capparis sepiaria. The formulations were characterized using appropriate techniques.Results: The gels' viscosity was in the range of 676.33 ± 121.76 to 20.00 ± 9.78 cP and in vitro whole blood kinetics showed their capability to induce a faster clotting rate. They also supported high cell viability of 80% with cellular migration and proliferation. Their antibacterial activity was significant against most bacteria strains used in the study.Conclusion: The gels' distinct features reveal their potential application as wound dressings for burn wounds.

Development of Alginate Hydrogels Incorporating Essential Oils Loaded in Chitosan Nanoparticles for Biomedical Applications

A hybrid alginate hydrogel-chitosan nanoparticle system suitable for biomedical applications was prepared. Chitosan (CS) was used as a matrix for the encapsulation of lavender (Lavandula angustifolia) essential oil (LEO) and Mentha (Mentha arvensis) essential oil (MEO). An aqueous solution of an acidic Natural Deep Eutectic Solvent (NADES), namely choline chloride/ascorbic acid in a 2:1 molar ratio, was used to achieve the acidic environment for the dissolution of chitosan and also played the role of the ionic gelator for the preparation of the chitosan nanoparticles (CS-NPs). The hydrodynamic diameter of the CS-MEO NPs was 130.7 nm, and the size of the CS-LEO NPs was 143.4 nm (as determined using Nanoparticle Tracking Analysis). The CS-NPs were incorporated into alginate hydrogels crosslinked with CaCl2. The hydrogels showed significant water retention capacity (>80%) even after the swollen sample was kept in the aqueous HCl solution (pH 1.2) for 4 h, indicating a good stability of the network. The hydrogels were tested (a) for their ability to absorb dietary lipids and (b) for their antimicrobial activity against Gram-positive and Gram-negative foodborne pathogens. The antimicrobial activity of the hybrid hydrogels was comparable to that of the widely used food preservative sodium benzoate 5% w/v.

Fabrication of l-proline enriched alginate dialdehyde-gelatin hydrogel thin films for efficient wound healing applications

Hydrogel-based wound management systems represent a promising avenue in tissue engineering for restoring and preserving the normal functionality of damaged tissues. Incorporating active components into hydrogel matrices enhances their suitability for biomedical applications. In this study, we investigated the integration of l-proline, a nonessential imino acid with largely unexplored roles in living systems, into alginate dialdehyde-gelatin hydrogel for wound healing purposes. Physicochemical properties of the resulting hydrogel film, termed ADAGLP, were meticulously evaluated, including wound healing efficacy in vitro and anti-biofilm activity against Gram-positive and Gram-negative microorganisms. Fourier-transform infrared spectroscopy (FTIR) analysis provided insights into the interaction between l-proline and ADAG. Films incorporating 0.5% l-proline were selected for comprehensive investigation. Comparative analysis revealed prolonged gelation time and increased water holding capacity of ADAGLP compared to ADAG films. Moreover, ADAGLP exhibited a significantly higher degradation rate (69.5 ± 3.2%) compared to ADAG (35.2 ± 1.6%). Remarkably, ADAGLP demonstrated cyto-compatibility, non-toxicity, and facilitated migration to the scratch area in vitro conditions. Notably, it exhibited potent anti-biofilm properties. Our findings suggest that ADAGLP hydrogel holds promise as a biomaterial for wound care, offering prolonged drug delivery and maintaining optimal moisture levels in wound areas. The incorporation of l-proline in the wound microenvironment may contribute to enhanced tissue remodeling, by inhibiting biofilm formation, further highlighting the potential of this hydrogel system in wound healing applications.

Enhanced wound healing properties of biodegradable PCL/alginate core-shell nanofibers containing Salvia abrotanoides essential oil and ZnO nanoparticles

Electrospun nanofibrous membranes, with their unique structural features, can potentially enhance wound healing through controlled delivery of active agents. Here, an innovative porous nanofibrous membrane was developed as a dressing patch with antibacterial and anti-inflammatory functionalities for cutaneous wound healing. Zinc oxide nanoparticles (ZnO NPs) and Salvia abrotanoides essential oil (SAEO) were incorporated into sodium alginate, which served as the shell. Poly(ε-caprolactone) was used as the core of coaxial electrospun wound dressing nanofibers (PCL/SA@ZnO/SAEO). With the addition of ZnO NPs and SAEO, the average diameter of nanofibers was 187 ± 51 nm, with improved tensile strength (4.7 ± 0.4 MPa), elongation at break (32.9 ± 2.1), and elastic modulus (21.4 ± 2.0). Concurrent application of ZnO NPs and SAEO increased antimicrobial activity against Staphylococcus aureus and Escherichia coli and promoted the proliferation, attachment, and viability (>90 %) of L929 cells. The PCL/SA@ZnO/SAEO scaffold accelerated the healing time with total wound healing over 14 days in mouse models carrying full-thickness wounds compared to the nanofibrous scaffold without additives. Histopathological examinations demonstrated better tissue regeneration, i.e., enhanced collagen deposition, improved re-epithelialization, and neovascularization, and increased quantity of hair follicles. Moreover, the chicken chorioallantoic membrane assay confirmed the synergistic angiogenic effects of SAEO and ZnO NPs. Finally, the in vitro and in vivo results proposed the bioactive core-shell nanofibers synthesized as encouraging wound dressing materials for hastening the healing of cutaneous wounds.

Advancing diabetic wound care: The role of copper-containing hydrogels

Diabetic wounds pose a significant challenge in healthcare due to their complex nature and the difficulties they present in treatment and healing. Impaired healing processes in individuals with diabetes can lead to complications and prolonged recovery times. However, recent advancements in wound healing provide reasons for optimism. Researchers are actively developing innovative strategies and therapies specifically tailored to address the unique challenges of diabetic wounds. One focus area is biomimetic hydrogel scaffolds that mimic the natural extracellular matrix, promoting angiogenesis, collagen deposition, and the healing process while also reducing infection risk. Copper nanoparticles and copper compounds incorporated into hydrogels release copper ions with antimicrobial, anti-inflammatory, and angiogenic properties. Copper reduces infection risk, modulates inflammatory response, and promotes tissue regeneration through cell adhesion, proliferation, and differentiation. Utilizing copper nanoparticles has transformative potential for expediting diabetic wound healing and improving patient outcomes while enhancing overall well-being by preventing severe complications associated with untreated wounds. It is crucial to write a review highlighting the importance of investigating the use of copper nanoparticles and compounds in diabetic wound healing and tissue engineering. These groundbreaking strategies hold the potential to transform the treatment of diabetic wounds, accelerating the healing process and enhancing patient outcomes.

Hydrogel-exosome system in tissue engineering: A promising therapeutic strategy

Characterized by their pivotal roles in cell-to-cell communication, cell proliferation, and immune regulation during tissue repair, exosomes have emerged as a promising avenue for "cell-free therapy" in clinical applications. Hydrogels, possessing commendable biocompatibility, degradability, adjustability, and physical properties akin to biological tissues, have also found extensive utility in tissue engineering and regenerative repair. The synergistic combination of exosomes and hydrogels holds the potential not only to enhance the efficiency of exosomes but also to collaboratively advance the tissue repair process. This review has summarized the advancements made over the past decade in the research of hydrogel-exosome systems for regenerating various tissues including skin, bone, cartilage, nerves and tendons, with a focus on the methods for encapsulating and releasing exosomes within the hydrogels. It has also critically examined the gaps and limitations in current research, whilst proposed future directions and potential applications of this innovative approach.

Current status and prospects of gelatin and its derivatives in oncological applications: Review

Treating cancer remains challenging due to the substantial side effects and unfavourable pharmacokinetic characteristics of antineoplastic medications, despite the progress made in comprehending the properties and actions of tumour cells in recent years. The advancement of biomaterials, such as stents, implants, personalised drug delivery systems, tailored grafts, cell sheets, and other transplantable materials, has brought about a significant transformation in healthcare and medicine in recent years. Gelatin is a very adaptable natural polymer that finds extensive application in healthcare-related industries owing to its favourable characteristics, including biocompatibility, biodegradability, affordability, and the presence of accessible chemical groups. Gelatin is used as a biomaterial in the biomedical sector for the creation of drug delivery systems (DDSs) since it may be applied to various synthetic procedures. Gelatin nanoparticles (NPs) have been extensively employed as carriers for drugs and genes, specifically targeting diseased tissues such as cancer, tuberculosis, and HIV infection, as well as treating vasospasm and restenosis. This is mostly due to their biocompatibility and ability to degrade naturally. Gelatins possess a diverse array of potential applications that require more elucidation. This review focuses on the use of gelatin and its derivatives in the diagnosis and treatment of cancer. The advancement of biomaterials and bioreactors, coupled with the increasing understanding of emerging applications for biomaterials, has enabled progress in enhancing the efficacy of tumour treatment.

Biomimetic Antifungal Materials: Countering the Challenge of Multidrug-Resistant Fungi

In light of rising public health threats like antifungal and antimicrobial resistance, alongside the slowdown in new antimicrobial development, biomimetics have shown promise as therapeutic agents. Multidrug-resistant fungi pose significant challenges as they quickly develop resistance, making traditional antifungals less effective. Developing new antifungals is also complicated by the need to target eukaryotic cells without harming the host. This review examines biomimetic antifungal materials that mimic natural biological mechanisms for targeted and efficient action. It covers a range of agents, including antifungal peptides, alginate-based antifungals, chitosan derivatives, nanoparticles, plant-derived polyphenols, and probiotic bacteria. These agents work through mechanisms such as disrupting cell membranes, generating reactive oxygen species, and inhibiting essential fungal processes. Despite their potential, challenges remain in terms of ensuring biocompatibility, optimizing delivery, and overcoming potential resistance. Production scalability and economic viability are also concerns. Future research should enhance the stability and efficacy of these materials, integrate multifunctional approaches, and develop sophisticated delivery systems. Interdisciplinary efforts are needed to understand interactions between these materials, fungal cells, and the host environment. Long-term health and environmental impacts, fungal resistance mechanisms, and standardized testing protocols require further study. In conclusion, while biomimetic antifungal materials represent a revolutionary approach to combating multidrug-resistant fungi, extensive research and development are needed to fully realize their potential.

Principles and Design of Bionic Hydrogel Adhesives for Skin Wound Treatment

Over millions of years of evolution, nature has developed a myriad of unique features that have inspired the design of adhesives for wound healing. Bionic hydrogel adhesives, capable of adapting to the dynamic movements of tissues, possess superior biocompatibility and effectively promote the healing of both external and internal wounds. This paper provides a systematic review of the design and principles of these adhesives, focusing on the treatment of skin wounds, and explores the feasibility of incorporating nature-inspired properties into their design. The adhesion mechanisms of bionic adhesives are analyzed from both chemical and physical perspectives. Materials from natural and synthetic polymers commonly used as adhesives are detailed regarding their biocompatibility and degradability. The multifunctional design elements of hydrogel adhesives for skin trauma treatment, such as self-healing, drug release, responsive design, and optimization of mechanical and physical properties, are further explored. The aim is to overcome the limitations of conventional treatments and offer a safer, more effective solution for the application of bionic wound dressings.

Injectable Hydrogels in Cardiovascular Tissue Engineering

Heart problems are quite prevalent worldwide. Cardiomyocytes and stem cells are two examples of the cells and supporting matrix that are used in the integrated process of cardiac tissue regeneration. The objective is to create innovative materials that can effectively replace or repair damaged cardiac muscle. One of the most effective and appealing 3D/4D scaffolds for creating an appropriate milieu for damaged tissue growth and healing is hydrogel. In order to successfully regenerate heart tissue, bioactive and biocompatible hydrogels are required to preserve cells in the infarcted region and to bid support for the restoration of myocardial wall stress, cell survival and function. Heart tissue engineering uses a variety of hydrogels, such as natural or synthetic polymeric hydrogels. This article provides a quick overview of the various hydrogel types employed in cardiac tissue engineering. Their benefits and drawbacks are discussed. Hydrogel-based techniques for heart regeneration are also addressed, along with their clinical application and future in cardiac tissue engineering.

Alginate-Chitosan Biodegradable and Biocompatible Based Hydrogel for Breast Cancer Immunotherapy and Diagnosis: A Comprehensive Review

Breast cancer is the most common type of cancer and the second leading cause of cancer-related mortality in females. There are many side effects due to chemotherapy and traditional surgery, like fatigue, loss of appetite, skin irritation, and drug resistance to cancer cells. Immunotherapy has become a hopeful approach toward cancer treatment, generating long-lasting immune responses in malignant tumor patients. Recently, hydrogel has received more attention toward cancer therapy due to its specific characteristics, such as decreased toxicity, fewer side effects, and better biocompatibility drug delivery to the particular tumor location. Researchers globally reported various investigations on hydrogel research for tumor diagnosis. The hydrogel-based multilayer platform with controlled nanostructure has received more attention for its antitumor effect. Chitosan and alginate play a leading role in the formation of the cross-link in a hydrogel. Also, they help in the stability of the hydrogel. This review discusses the properties, preparation, biocompatibility, and bioavailability of various research and clinical approaches of the multipolymer hydrogel made of alginate and chitosan for breast cancer treatment. With a focus on cases of breast cancer and the recovery rate, there is a need to find out the role of hydrogel in drug delivery for breast cancer treatment.

Time-Separated Pulse Release-Activation of an Enzyme from Alginate-Polyethylenimine Hydrogels Using Electrochemically Generated Local pH Changes

β-Glucosidase (EC 3.2.1.21) from sweet almond was encapsulated into pH-responsive alginate-polyethylenimine (alginate-PEI) hydrogel. Then, electrochemically controlled cyclic local pH changes resulting from ascorbate oxidation (acidification) and oxygen reduction (basification) were used for the pulsatile release of the enzyme from the composite hydrogel. Activation of the enzyme was controlled by the very same pH changes used for β-glucosidase release, separating these two processes in time. Importantly, the activity of the enzyme, which had not been released yet, was inhibited due to the buffering effect of PEI present in the gel. Thus, only a portion of the released enzyme was activated. Both enzymatic activity and release were monitored by confocal fluorescence microscopy and regular fluorescent spectroscopy. Namely, commercially available very little or nonfluorescent substrate 4-methylumbelliferyl-β-d-glucopyranoside was hydrolyzed by β-glucosidase to produce a highly fluorescent product 4-methylumbelliferone during the activation phase. At the same time, labeling of the enzyme with rhodamine B isothiocyanate was used for release observation. The proposed work represents an interesting smart release-activation system with potential applications in biomedical field.

Transdermal Delivery of Cannabidiol for the Management of Acute Inflammatory Pain: A Comprehensive Review of the Literature

The emerging field of nanotechnology has paved the way for revolutionary advancements in drug delivery systems, with nanosystems emerging as a promising avenue for enhancing the therapeutic potential and the stability of various bioactive compounds. Among these, cannabidiol (CBD), the non-psychotropic compound of the Cannabis sativa plant, has gained attention for its therapeutic properties. Consequently, researchers have devoted significant efforts to unlock the full potential of CBD's clinical benefits, where various nanosystems and excipients have emerged to overcome challenges associated with its bioavailability, stability, and controlled release for its transdermal application. Therefore, this comprehensive review aims to explain CBD's role in managing acute inflammatory pain and offers an overview of the state of the art of existing delivery systems and excipients for CBD. To summarize this review, a summary of the cannabinoids and therapeutical targets of CBD will be discussed, followed by its conventional modes of administration. The transdermal route of administration and the current topical and transdermal delivery systems will also be reviewed. This review will conclude with an overview of in vivo techniques that allow the evaluation of the anti-inflammatory and analgesic potentials of these systems.

High-Level Extracellular Production of a Trisaccharide-Producing Alginate Lyase AlyC7 in Escherichia coli and Its Agricultural Application

Alginate oligosaccharides (AOS), products of alginate degradation by endotype alginate lyases, possess favorable biological activities and have broad applications. Although many have been reported, alginate lyases with homogeneous AOS products and secretory production by an engineered host are scarce. Herein, the alginate lyase AlyC7 from Vibrio sp. C42 was characterized as a trisaccharide-producing lyase exhibiting high activity and broad substrate specificity. With PelB as the signal peptide and 500 mM glycine as the additive, the extracellular production of AlyC7 in Escherichia coli reached 1122.8 U/mL after 27 h cultivation in Luria-Bertani medium. The yield of trisaccharides from sodium alginate degradation by the produced AlyC7 reached 758.6 mg/g, with a purity of 85.1%. The prepared AOS at 20 μg/mL increased the root length of lettuce, tomato, wheat, and maize by 27.5%, 25.7%, 9.7%, and 11.1%, respectively. This study establishes a robust foundation for the industrial and agricultural applications of AlyC7.

Production of letrozole-loaded alginate oxide-gelatin microgels using microfluidic systems for drug delivery applications

Microfluidic systems are capable of producing microgels with a monodisperse size distribution and a spherical shape due to their laminar flow and superior flow. A significant challenge in producing these drug-carrying microgels is simultaneous drug loading into microgels. Various factors such as the type of polymer, the type of drug, the volume ratio of the drug to the polymer, and the geometry of the microfluidic system used to generate microgels can effectively address these challenges. The overall goal of this study was to produce mono-disperse drug-carrying microgels capable of controlled drug release. To achieve this goal, this study used a stream-focused microfluidic chip containing a coating current to prevent chip clogging. Alginate oxide was synthesized with a 30 % oxidation percentage. Alginate oxide, gelatin, and compositions of them with volume ratios of 50-50, 70-30, and 30-70, by determining their appropriate weight percentage, were used for the controlled release of letrozole. The properties of the produced microgels were measured through various tests such as drug release test, loading percentage, SEM, FTIR, swelling ratio, and dimensional stability. It was found that microgels made of a combination of alginate oxide-gelatin with volume ratios of 70-30 had a good swelling ratio and structural stability. The drug loading percentages for alginate, alginate oxide, and alginate oxide-gelatin with volume ratios of 50-50 and 30-70, respectively, were 56 %, 68 %, and 66 %, 61 % and the alginate oxide-gelatin with a volume ratio of 70-30 compared to other samples had over 70 % drug loading percentages. Furthermore, samples of alginate, alginate oxide, and alginate oxide-gelatin with volume ratios of 50-50 and 30-70 had 94 %, 63 %, 56 %, and 68 % drug release in 13 days, respectively. However, alginate oxide-gelatin with a volume ratio of 70-30 had a release rate of about 50 % in 13 days, which is a more controlled release for letrozole compared to the volume ratios of 50-50 and 30-70. Examining the drug release profile, it was concluded that drug release follows the Higuchi model and therefore follows Fick's first law of diffusion. It can be concluded that the combination of alginate oxide-gelatin produces more suitable microgels than alginate and alginate oxide for the controlled-release of letrozole. A comparison of microgels of alginate oxide and gelatin with volume ratios of 50-50 and 70-30 had better results for the cytotoxicity study compared to other samples.

Alginate and Chitosan-Based Hydrogel Enhance Antibacterial Agent Activity on Topical Application

Untreated topical infections can become chronic, posing serious health issues. Optimal skin adherence is crucial in addressing such infections. In this context, chitosan and alginate emerge as promising candidates for use as a foundation in the development of topical hydrogels. The aim of this review is to examine the literature on topical hydrogel formulations that use chitosan and alginate as foundations, specifically in the context of topical antibacterial agents. The research methodology involves a literature review by examining articles published in databases such as PubMed, Scopus, ScienceDirect, and Google Scholar. The keywords employed during the research were "Alginate", "Chitosan", "Hydrogel", and "Antibacterial". Chitosan and alginate serve as bases in topical hydrogels to deliver various active ingredients, particularly antibacterial agents, as indicated by the search results. Both have demonstrated significant antibacterial effectiveness, as evidenced by a reduction in bacterial colony counts and an increase in inhibition zones. This strongly supports the idea that chitosan and alginate could be used together to make topical hydrogels that kill bacteria that work well. In conclusion, chitosan and alginate-based hydrogels show great potential in treating bacterial infections on the skin surface. The incorporation of chitosan and alginate into hydrogel formulations aids in retaining antibacterial agents, allowing for their gradual release over an optimal period. Therefore, hydrogels specifically formulated with chitosan and alginate have the potential to serve as a solution to address challenges in the treatment of topical bacterial infections.

Cellulose-alginate hydrogels and their nanocomposites for water remediation and biomedical applications

In the last decade, both cellulose and alginate polysaccharides have been extensively utilized for the synthesis of biocompatible hydrogels because of their alluring characteristics like low cost, biodegradability, hydrophilicity, biodegradability, ease of availability and non-toxicity. The presence of abundant hydrophilic functional groups (like carboxyl and hydroxyl) on the surface of cellulose and alginate or their derivatives makes these materials promising candidates for the preparation of hydrogels with appealing structures and characteristics, leading to growing research in water treatment and biomedical fields. These two polysaccharides are typically blended together to improve hydrogels' desired qualities (mechanical strength, adsorption properties, cellulose/alginate yield). So, keeping in view their extensive applicability, in the present review article, recent advances in the development of cellulose/nanocellulose-alginate-based hydrogels and their relevance in water treatment (adsorption of dyes, heavy metals, etc.) and biomedical field (wound healing, tissue engineering, drug delivery) has been reviewed. Further, impact of other inorganic/organic additives in cellulose/nanocellulose-alginate-based hydrogels properties like contaminants adsorption, drug delivery, tissue engineering, etc., has also been studied. Moreover, the current difficulties and future prospects of nanocellulose-alginate-based hydrogels regarding their water purification and biomedical applications are also discussed at the end.

Fabrication of Alginate/Ozoile Gel Microspheres by Electrospray Process

Natural polymers, such as alginate and chitosan, are widely exploited for drug delivery applications due to their biocompatibility, low toxicity, and sustainable sourcing. In this study, pH-responsive gel microspheres were fabricated from an alginate/Ozoile emulsion. Ozoile (Stable Ozonides) is a biological inducer, derived from olive oil, which stimulates the endogenous defense system by promoting the repair of tissue damage and restoration of proper physiology through the regulation of gene transcription. Here, the versatile and cost-effective electrospray technique without the use of organic solvents was used to fabricate alginate/Ozoile microspheres with high throughput. The process parameters (voltage, flow rate, and needle gauge) were optimized to obtain microspheres with good sphericity factor and tailored diameter (250-700 μm). The microspheres were additionally optimized through a chitosan coating to enhance their stability and regulate the gel matrix's degradation process. Morphological analysis, FTIR spectroscopy, and degradation tests confirmed the structural integrity and pH-responsive behavior of the gel microspheres. This research offers a promising route for targeted drug delivery systems, particularly in applications related to the modulation of oxidative stress and management of inflammation.

Marginal adaptation, physicochemical and rheological properties of treated dentin matrix hydrogel as a novel injectable pulp capping material for dentin regeneration

BACKGROUND

Treated dentin matrix hydrogel (TDMH) has been introduced as a novel injectable direct pulp capping material. In this regard, this study aimed to evaluate its marginal adaptation, physicochemical and rheological properties for the development of clinically feasible TDMH.

METHODS

TDMH was applied to the pulp floor of prepared Class I cavities (n = 5), marginal adaptation was assessed by SEM at 1000 X magnification to detect gap between dentin and filling material. Five syringes were filled with TDMH and placed between the compression plates of a universal testing machine to evaluate injectability and gelation time was also evaluated by test vial inverting method. The microstructures of lyophilized TDMH were observed by SEM. Moreover, TDMH discs (n = 5) were prepared and the water uptake (%) was determined based on the equilibrium swelling theory state of hydrogels. Its solubility was measured after one week by the ISO standard method. Rheological behaviours of TDMH (n = 5) were analysed with a rotational rheometer by computing their complex shear modulus G* and their associated storage modulus (G') and loss modulus (G''). Statistical analysis was performed using F test (ANOVA) with repeated measures and Post Hoc Test (p = 0.05).

RESULTS

TDMH presented an overall 92.20 ± 2.95% of continuous margins. It exhibited gelation during the first minute, and injectability mean was 66 ± 0.36%. TDMH showed a highly porous structure, and the pores were interconnected with an average diameter about 5.09 ± 3.17 μm. Swelling equilibrium gradually reached at 6 days up to 377%. The prepared hydrogels and maintained their shape after absorbing over three times their original weight of water. TDMH fulfilled the requirements of ISO 6876, demonstrating a weight loss of 1.98 ± 0.09% and linear viscoelastic behaviour with G` 479.2 ± 12.7 and G`` 230.8 ± 13.8.

CONCLUSIONS

TDMH provided good marginal adaptation, appropriate physicochemical and viscoelastic properties support its use as a novel direct pulp capping material in future clinical applications.

Alginate-Gelatin Hydrogel Scaffolds; An Optimization of Post-Printing Treatment for Enhanced Degradation and Swelling Behavior

The generation of 3D structures comprises three interlinked phases: material development, the printing process, and post-printing treatment. Numerous factors control all three phases, making the optimization of the entire process a challenging task. Until now, the state of the art has mainly focused on optimizing material processability and calibration of the printing process. However, after the successful Direct Ink Writing (DIW) of a hydrogel scaffold, the post-printing stage holds equal importance, as this allows for the treatment of the structure to ensure the preservation of its structural integrity for a duration that is sufficient to enable successful cell attachment and proliferation before undergoing degradation. Despite this stage's pivotal role, there is a lack of extensive literature covering its optimization. By studying the crosslinking factors and leveling the post-treatment settings of alginate-gelatin hydrogel, this study proposes a method to enhance scaffolds' degradation without compromising the targeted swelling behavior. It introduces an experimental design implementing the Response Surface Methodology (RSM) Design of Experiments (DoE), which elucidated the key parameters influencing scaffold degradation and swelling, and established an alginate ratio of 8% and being immersed for 15 min in 0.248 M CaCl2 as the optimal level configuration that generates a solution of 0.964 desirability, reaching a degradation time of 19.654 days and the swelling ratio of 50.00%.

Development of Biocompatible 3D-Printed Artificial Blood Vessels through Multidimensional Approaches

Within the human body, the intricate network of blood vessels plays a pivotal role in transporting nutrients and oxygen and maintaining homeostasis. Bioprinting is an innovative technology with the potential to revolutionize this field by constructing complex multicellular structures. This technique offers the advantage of depositing individual cells, growth factors, and biochemical signals, thereby facilitating the growth of functional blood vessels. Despite the challenges in fabricating vascularized constructs, bioprinting has emerged as an advance in organ engineering. The continuous evolution of bioprinting technology and biomaterial knowledge provides an avenue to overcome the hurdles associated with vascularized tissue fabrication. This article provides an overview of the biofabrication process used to create vascular and vascularized constructs. It delves into the various techniques used in vascular engineering, including extrusion-, droplet-, and laser-based bioprinting methods. Integrating these techniques offers the prospect of crafting artificial blood vessels with remarkable precision and functionality. Therefore, the potential impact of bioprinting in vascular engineering is significant. With technological advances, it holds promise in revolutionizing organ transplantation, tissue engineering, and regenerative medicine. By mimicking the natural complexity of blood vessels, bioprinting brings us one step closer to engineering organs with functional vasculature, ushering in a new era of medical advancement.

Biomaterials-mediated CRISPR/Cas9 delivery: recent challenges and opportunities in gene therapy

The use of biomaterials in delivering CRISPR/Cas9 for gene therapy in infectious diseases holds tremendous potential. This innovative approach combines the advantages of CRISPR/Cas9 with the protective properties of biomaterials, enabling accurate and efficient gene editing while enhancing safety. Biomaterials play a vital role in shielding CRISPR/Cas9 components, such as lipid nanoparticles or viral vectors, from immunological processes and degradation, extending their effectiveness. By utilizing the flexibility of biomaterials, tailored systems can be designed to address specific genetic diseases, paving the way for personalized therapeutics. Furthermore, this delivery method offers promising avenues in combating viral illnesses by precisely modifying pathogen genomes, and reducing their pathogenicity. Biomaterials facilitate site-specific gene modifications, ensuring effective delivery to infected cells while minimizing off-target effects. However, challenges remain, including optimizing delivery efficiency, reducing off-target effects, ensuring long-term safety, and establishing scalable production techniques. Thorough research, pre-clinical investigations, and rigorous safety evaluations are imperative for successful translation from the laboratory to clinical applications. In this review, we discussed how CRISPR/Cas9 delivery using biomaterials revolutionizes gene therapy and infectious disease treatment, offering precise and safe editing capabilities with the potential to significantly improve human health and quality of life.

Curcumin-Sodium Alginate and Curcumin-Chitosan Conjugates as Drug Delivery Systems: An Interesting Rheological Behaviour

The conjugation of polyphenols is a valuable strategy with which to confer tailored properties to polymeric materials of biomedical interest. Within this investigation, we aim to explore the possibility to use this synthetic approach to increase the viscosity of conjugates, thus allowing the release of a loaded therapeutic to be better controlled over time than in neat polyphenols. Curcumin (CUR) was conjugated to sodium alginate (CA) and chitosan (CS) with functionalisation degrees of 9.2 (SA-CUR) and 15.4 (CS-CUR) mg g-1. Calorimetric analyses showed higher degrees of chain rigidity upon conjugation, with a shift of the degradation peaks to higher temperatures (from 239 to 245 °C and from 296 to 303 °C for SA-CUR and CS-CUR, respectively). Rheological analyses were used to prove the enhanced interconnection between the polymer chains in the conjugates, confirmed by the weak gel parameters, A and z. Moreover, the typical non-Newtonian behaviour of the high-molecular-weight polysaccharides was recorded, together with an enhancement of the activation energy, Ea, in CS-CUR vs. CS (opposite behaviour recorded for SA-CUR vs. SA). The evaluation of the delivery performance (of Doxorubicin as a model drug) showed sustained release profiles, opening opportunities for the development of controlled delivery systems.