A PEG-Based Hydrogel for Effective Wound Care Management

Incorporation of Resveratrol-Hydroxypropyl-β-Cyclodextrin Complexes into Hydrogel Formulation for Wound Treatment

Resveratrol could be applied in wound healing therapies because of its antioxidant, anti-inflammatory and antibacterial effects. However, the main limitation of resveratrol is its low aqueous solubility. In this study, resveratrol was included in hydroxypropyl-β-cyclodextrin complexes and further formulated in Pluronic F-127 hydrogels for wound treatment therapy. IR-spectroscopy and XRD analysis confirmed the successful incorporation of resveratrol into complexes. The wound-healing ability of these complexes was estimated by a scratch assay on fibroblasts, which showed a tendency for improvement of the effect of resveratrol after complexation. The antimicrobial activity of resveratrol in aqueous dispersion and in the complexes was evaluated on methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Candida albicans strains. The results revealed a twofold decrease in the MIC and stronger inhibition of the metabolic activity of MRSA after treatment with resveratrol in the complexes compared to the suspended drug. Furthermore, the complexes were included in Pluronic hydrogel, which provided efficient drug release and appropriate viscoelastic properties. The formulated hydrogel showed excellent biocompatibility which was confirmed via skin irritation test on rabbits. In conclusion, Pluronic hydrogel containing resveratrol included in hydroxypropyl-β-cyclodextrin complexes is a promising topical formulation for further studies directed at wound therapy.

Bringing innovative wound care polymer materials to the market: Challenges, developments, and new trends

The development of innovative products for treating acute and chronic wounds has become a significant topic in healthcare, resulting in numerous products and innovations over time. The growing number of patients with comorbidities and chronic diseases, which may significantly alter, delay, or inhibit normal wound healing, has introduced considerable new challenges into the wound management scenario. Researchers in academia have quickly identified promising solutions, and many advanced wound healing materials have recently been designed; however, their successful translation to the market remains highly complex and unlikely without the contribution of industry experts. This review article condenses the main aspects of wound healing applications that will serve as a practical guide for researchers working in academia and industry devoted to designing, evaluating, validating, and translating polymer wound care materials to the market. The article highlights the current challenges in wound management, describes the state-of-the-art products already on the market and trending polymer materials, describes the regulation pathways for approval, discusses current wound healing models, and offers a perspective on new technologies that could soon reach consumers. We envision that this comprehensive review will significantly contribute to highlighting the importance of networking and exchanges between academia and healthcare companies. Only through the joint of these two actors, where innovation, manufacturing, regulatory insights, and financial resources act in harmony, can wound care products be developed efficiently to reach patients quickly and affordably.

Enhanced Hemostatic and Procoagulant Efficacy of PEG/ZnO Hydrogels: A Novel Approach in Traumatic Hemorrhage Management

Managing severe bleeding, particularly in soft tissues and visceral injuries, remains a significant challenge in trauma and surgical care. Traditional hemostatic methods often fall short in wet and dynamic environments. This study addresses the critical issue of severe bleeding in soft tissues, proposing an innovative solution using a polyethylene glycol (PEG)-based hydrogel combined with zinc oxide (ZnO). The developed hydrogel forms a dual-network structure through amide bonds and metal ion chelation, resulting in enhanced mechanical properties and adhesion strength. The hydrogel, exhibiting excellent biocompatibility, is designed to release zinc ions, promoting coagulation and accelerating hemostasis. Comprehensive characterization, including gelation time, rheological properties, microstructure analysis, and swelling behavior, demonstrates the superior performance of the PEG/ZnO hydrogel compared to traditional PEG hydrogels. Mechanical tests confirm increased compression strength and adhesive properties, which are crucial for withstanding tissue dynamics. In vitro assessments reveal excellent biocompatibility and enhanced procoagulant ability attributed to ZnO. Moreover, in vivo experiments using rat liver and tail bleeding models demonstrate the remarkable hemostatic performance of the PEG/ZnO hydrogel, showcasing its potential for acute bleeding treatment in both visceral and peripheral scenarios.

Hydrogels and Wound Healing: Current and Future Prospects

The care and rehabilitation of acute and chronic wounds have a significant social and economic impact on patients and global health. This burden is primarily due to the adverse effects of infections, prolonged recovery, and the associated treatment costs. Chronic wounds can be treated with a variety of approaches, which include surgery, negative pressure wound therapy, wound dressings, and hyperbaric oxygen therapy. However, each of these strategies has an array of limitations. The existing dry wound dressings lack functionality in promoting wound healing and exacerbating pain by adhering to the wound. Hydrogels, which are commonly polymer-based and swell in water, have been proposed as potential remedies due to their ability to provide a moist environment that facilitates wound healing. Their unique composition enables them to absorb wound exudates, exhibit shape adaptability, and be modified to incorporate active compounds such as growth factors and antibacterial compounds. This review provides an updated discussion of the leading natural and synthetic hydrogels utilized in wound healing, details the latest advancements in hydrogel technology, and explores alternate approaches in this field. Search engines Scopus, PubMed, Science Direct, and Web of Science were utilized to review the advances in hydrogel applications over the last fifteen years.

Functional hydrogel-based wound dressings: A review on biocompatibility and therapeutic efficacy

Chronic wounds, burns, and surgical incisions represent critical healthcare challenges that significantly impact patient quality of life and strain healthcare resources. In response to these pressing needs, the field of wound healing has witnessed a radical advancement with the emergence of functional hydrogel-based dressings. This review article underscores the severity and importance of this transformative study in the domain of wound healing. The hydrogel matrix offers a moist and supportive environment that facilitates cellular migration, proliferation, and tissue regeneration, vital for efficient wound closure. Their conformable nature ensures patient comfort, reducing pain and uneasiness during dressing changes, particularly in chronic wounds where frequent interventions are required. Beyond their structural merits, functional hydrogel dressings possess the capability of incorporating bioactive molecules such as growth factors and antimicrobial agents. This facilitates targeted and sustained delivery of therapeutics directly to the wound site, addressing the multifactorial nature of chronic wounds and enhancing the healing trajectory. The integration of advanced nanotechnology has propelled the design of hydrogel dressings with enhanced mechanical strength and controlled drug release profiles, amplifying their therapeutic potential. In conclusion, the significance of this study lies in its ability to revolutionize wound healing practices and positively impact the lives of countless individuals suffering from chronic wounds and burns. As this transformative technology gains momentum, it holds the promise of addressing a major healthcare burden worldwide, thus heralding a new era in wound care management.

Research progress related to thermosensitive hydrogel dressings in wound healing: a review

Wound healing is a dynamic and complex process in which the microenvironment at the wound site plays an important role. As a common material for wound healing, dressings accelerate wound healing and prevent external wound infections. Hydrogels have become a hot topic in wound-dressing research because of their high water content, good biocompatibility, and adjustable physical and chemical properties. Intelligent hydrogel dressings have attracted considerable attention because of their excellent environmental responsiveness. As smart polymer hydrogels, thermosensitive hydrogels can respond to small temperature changes in the environment, and their special properties make them superior to other hydrogels. This review mainly focuses on the research progress in thermosensitive intelligent hydrogel dressings for wound healing. Polymers suitable for hydrogel formation and the appropriate molecular design of the hydrogel network to achieve thermosensitive hydrogel properties are discussed, followed by the application of thermosensitive hydrogels as wound dressings. We also discuss the future perspectives of thermosensitive hydrogels as wound dressings and provide systematic theoretical support for wound healing.

Modern Approaches in Wounds Management

Wound management represents a well-known continuous challenge and concern of the global healthcare systems worldwide. The challenge is on the one hand related to the accurate diagnosis, and on the other hand to establishing an effective treatment plan and choosing appropriate wound care products in order to maximize the healing outcome and minimize the financial cost. The market of wound dressings is a dynamic field which grows and evolves continuously as a result of extensive research on developing versatile formulations with innovative properties. Hydrogels are one of the most attractive wound care products which, in many aspects, are considered ideal for wound treatment and are widely exploited for extension of their advantages in healing process. Smart hydrogels (SHs) offer the opportunities of the modulation physico-chemical properties of hydrogels in response to external stimuli (light, pressure, pH variations, magnetic/electric field, etc.) in order to achieve innovative behavior of their three-dimensional matrix (gel-sol transitions, self-healing and self-adapting abilities, controlled release of drugs). The SHs response to different triggers depends on their composition, cross-linking method, and manufacturing process approach. Both native or functionalized natural and synthetic polymers may be used to develop stimuli-responsive matrices, while the mandatory characteristics of hydrogels (biocompatibility, water permeability, bioadhesion) are preserved. In this review, we briefly present the physiopathology and healing mechanisms of chronic wounds, as well as current therapeutic approaches. The rational of using traditional hydrogels and SHs in wound healing, as well as the current research directions for developing SHs with innovative features, are addressed and discussed along with their limitations and perspectives in industrial-scale manufacturing.

A new perspective on quantitative assessment of photodynamic therapy mediated hydrogel nanocomposite in wound healing using objective biospeckle and morphological local-gradient

Skin wounding is a serious public health issue, especially when considering factors that accelerate tissue recovery. Consequently, the use of photodynamic therapy (PDT) as an effective wound-healing treatment has attracted more scientific attention. Although assessing the wound healing rate is crucial for appropriate monitoring of the probability of wound healing and evaluating the treatment efficiency, the currently used techniques lack the ability to provide such information. Therefore, this study has two aims, first, it contributes to the development of a new image-guided biospeckle system for quantitative monitoring of skin wound healing rate. Second, it evaluates the potential of using a novel synthesized PDT-mediated polyethylene glycol fabric with methylene blue (PEG-MB) hydrogel nanocomposite in accelerating wound healing. The proposed imaging system initially acquires raw biospeckle images from the wound regions of adult healthy albino mice treated with the synthesized hydrogel nanocomposite. Each raw biospeckle image is then converted into maps of morphological local-gradient matrices implemented from the combination of dilation and erosion operations at different radii up to 25 pixels. Subsequently, their intensity histogram statistics are computed, taking central moments as the feature set. Final characterization is achieved via a linear combination of the biospeckle statistics maintaining as much variance as possible using principal component analysis (PCA). The results confirmed by cytokine concentration measurement and histological investigation demonstrate that the innovative biospeckle image-guided system is ideal for investigating wound healing and suggest the potential of the hydrogel nanocomposite as an active dressing.

The potential therapeutic impact of a topical bacteriophage preparation in treating Pseudomonas aeruginosa-infected burn wounds in mice

Aim

This study compared a topical formulation containing lytic phages with a routine antibiotic in the murine model of burn/Pseudomonas aeruginosa infected wound healing.

Methods & Materials

Isolated and purified lytic bacteriophages from hospital sewage were added to the polyethylene glycol (PEG) based ointment. A second-degree burned wound on the back of twenty-four adult female mice was created. The wounds were infected subcutaneously with 100 μL of 1 × 102-3 CFU/mL P. aeruginosa. After 24 h, mice were randomly assigned to one of four groups: mice received a standard antibiotic (antibiotic-treated group), mice received an ointment without bacteriophage (PEG-based group), mice received a PEG-ointment with bacteriophage (bacteriophage-treated group), or mice received no treatment (untreated-control group). Every two days, the contraction of burned wounds, physical activity, and rectal body temperature were recorded. On day 10, mice were sacrificed, and the wounds were cut off and evaluated histopathologically.

Results

In ointments containing PEG, bacteriophages were active and stable. The mice receiving bacteriophage and PEG-based ointment had substantially different wound contraction in primary wound healing (P = 0.001). When compared to the control group, the bacteriophage-treated group showed significant variations in wound contraction (P = 0.001). The wound contraction changed significantly between the antibiotic and PEG-based groups (P = 0.002). In all groups, physical activity in mice improved over time, with significant differences (P = 0.001). When the 8th day was compared to the days 2, 4, and 6, significant changes were found (P = 0.001, P = 0.02, and P = 0.02, respectively). Both the positive control and bacteriophage-treated groups showed perfect wound healing histopathologically. However, no significant variations in microscopic histopathological criteria were found between the groups.

Conclusion

Formulated phage ointment could be a promising approach for treating infected burn wounds infected by P. aeruginosa in mice with no allergic reactions.

Development and Evaluation of Self-Microemulsifying Drug Delivery System for Improving Oral Absorption of Poorly Water-Soluble Olaparib

The purpose of this study is to develop and evaluate a self-microemulsifying drug delivery system (SMEDDS) to improve the oral absorption of poorly water-soluble olaparib. Through the solubility test of olaparib in various oils, surfactants and co-surfactants, pharmaceutical excipients were selected. Self-emulsifying regions were identified by mixing the selected materials at various ratios, and a pseudoternary phase diagram was constructed by synthesizing these results. The various physicochemical properties of microemulsion incorporating olaparib were confirmed by investigating the morphology, particle size, zeta potential, drug content and stability. In addition, the improved dissolution and absorption of olaparib were also confirmed through a dissolution test and a pharmacokinetic study. An optimal microemulsion was generated in the formulation of Capmul^® MCM 10%, Labrasol^® 80% and PEG 400 10%. The fabricated microemulsions were well-dispersed in aqueous solutions, and it was also confirmed that they were maintained well without any problems of physical or chemical stability. The dissolution profiles of olaparib were significantly improved compared to the value of powder. Associated with the high dissolutions of olaparib, the pharmacokinetic parameters were also greatly improved. Taken together with the results mentioned above, the microemulsion could be an effective tool as a formulation for olaparib and other similar drugs.

Biomaterial mediated immunomodulation: An interplay of material environment interaction for ameliorating wound regeneration

Chronic wounds are the outcome of an imbalanced inflammatory response caused by sustenance of immune microenvironment. In this context, tissue engineered graft played great role in healing wounds but faced difficulty in scar remodelling, immune rejection and poor vascularization. All the limitations faced are somewhere linked with the immune cells involved in healing. In this consideration, immunomodulatory biomaterials bridge a large gap with the delivery of modulating factors for triggering key inflammatory cells responsible towards interplay in the wound micro-environment. Inherent physico-chemical properties of biomaterials substantially determine the nature of cell-materials interaction thereby facilitating differential cytokine gradient involved in activation or suppression of inflammatory signalling pathways, and followed by surface marker expression. This review aims to systematically describe the interplay of immune cells involved in different phases in the wound microenvironment and biomaterials. Additionally, it also focuses on modulating innate immune cell responses in the context of triggering the halted phase of the wound healing, i.e., inflammatory phase. The various strategies are highlighted for modulation of wound microenvironment towards wound regeneration including stem cells, cytokines, growth factors, vitamins, and anti-inflammatory agents to induce interactive ability of biomaterials with immune cells. The last section focuses on prospective approaches and current potential strategies for wound regeneration. This includes the development of different models to bridge the gap between mouse models and human patients. Emerging new tools to study inflammatory response owing to biomaterials and novel strategies for modulation of monocyte and macrophage behaviour in the wound environment are also discussed.

Extracellular Vesicle-Based Hydrogels for Wound Healing Applications

Hydrogels and extracellular vesicle-based therapies have been proposed as emerging therapeutic assets in wound closure. The combination of these elements has given good results in managing chronic and acute wounds. The intrinsic characteristics of the hydrogels in which the extracellular vesicles (EVs) are loaded allow for overcoming barriers, such as the sustained and controlled release of EVs and the maintenance of the pH for their conservation. In addition, EVs can be obtained from different sources and through several isolation methods. However, some barriers must be overcome to transfer this type of therapy to the clinic, for example, the production of hydrogels containing functional EVs and identifying long-term storage conditions for EVs. The aim of this review is to describe the reported EV-based hydrogel combinations, along with the obtained results, and analyze future perspectives.

Injectable self-healing chitosan-based POSS-PEG hybrid hydrogel as wound dressing to promote diabetic wound healing

Promoting the healing of diabetic wounds remains a major challenge in scientific research today. A star-like eight-arm cross-linker octafunctionalized POSS of benzaldehyde-terminated polyethylene glycol (POSS-PEG-CHO) was synthesized, and crosslinked with hydroxypropyltrimethyl ammonium chloride chitosan (HACC) via Schiff base reaction to obtain Chitosan-based POSS-PEG hybrid hydrogels. The designed composite hydrogels exhibited strong mechanical strength, injectability, excellent self-healing efficiency, good cytocompatibility and antibacterial properties. Furthermore, the composite hydrogels could accelerate cells migration and proliferation, as expected by remarkably promoting wound healing in diabetic mice. The wounds treated with the composite hydrogels displayed faster regeneration of epithelial tissue, fewer inflammatory cells, more collagen deposition and higher expression level of VEGF. Therefore, Chitosan-based POSS-PEG hybrid hydrogel has great application potential as a dressing for promoting the healing of diabetic wounds.

Growth Factor Binding Peptides in Poly (Ethylene Glycol) Diacrylate (PEGDA)-Based Hydrogels for an Improved Healing Response of Human Dermal Fibroblasts

Growth factors (GF) are critical cytokines in wound healing. However, the direct delivery of these biochemical cues into a wound site significantly increases the cost of wound dressings and can lead to a strong immunological response due to the introduction of a foreign source of GFs. To overcome this challenge, we designed a poly(ethylene glycol) diacrylate (PEGDA) hydrogel with the potential capacity to sequester autologous GFs directly from the wound site. We demonstrated that synthetic peptide sequences covalently tethered to PEGDA hydrogels physically retained human transforming growth factor beta 1 (hTGFβ1) and human vascular endothelial growth factor (hVEGF) at 3.2 and 0.6 ng/mm², respectively. In addition, we demonstrated that retained hTGFβ1 and hVEGF enhanced human dermal fibroblasts (HDFa) average cell surface area and proliferation, respectively, and that exposure to both GFs resulted in up to 1.9-fold higher fraction of area covered relative to the control. After five days in culture, relative to the control surface, non-covalently bound hTGFβ1 significantly increased the expression of collagen type I and hTGFβ1 and downregulated vimentin and matrix metalloproteinase 1 expression. Cumulatively, the response of HDFa to hTGFβ1 aligns well with the expected response of fibroblasts during the early stages of wound healing.

A Review on Recent Progress of Stingless Bee Honey and Its Hydrogel-Based Compound for Wound Care Management

Stingless bee honey has a distinctive flavor and sour taste compared to Apis mellifera honey. Currently, interest in farming stingless bees is growing among rural residents to meet the high demand for raw honey and honey-based products. Several studies on stingless bee honey have revealed various therapeutic properties for wound healing applications. These include antioxidant, antibacterial, anti-inflammatory, and moisturizing properties related to wound healing. The development of stingless bee honey for wound healing applications, such as incorporation into hydrogels, has attracted researchers worldwide. As a result, the effectiveness of stingless bee honey against wound infections can be improved in the future to optimize healing rates. This paper reviewed the physicochemical and therapeutic properties of stingless bee honey and its efficacy in treating wound infection, as well as the incorporation of stingless bee honey into hydrogels for optimized wound dressing.

Preparation of thyme oil loaded κ-carrageenan-polyethylene glycol hydrogel membranes as wound care system

The present study is aimed at fabricating thyme oil loaded hydrogel membranes composed of κ-carrageenan (CG) and polyethylene glycol (PEG), which can provide moist environment and prevent infections for rapid wound healing. Membranes were prepared with different amounts of PEG via solvent casting technique under ambient conditions. Physicochemical properties of CG-PEG membranes as a function of the PEG content were investigated. The surface morphology of membranes displayed smoother surfaces with increasing PEG content up to 40%. In addition, the interaction of PEG with CG polymer chains was evaluated in terms of Free and bound PEG fraction within the membrane matrix. Furthermore, thyme oil (TO) was added to enhance the antibacterial properties of CG-PEG membranes. These membranes showed >95% antimicrobial activity against both gram-positive and gram-negative bacteria depending on the TO content. Suggesting the great potential of these membranes as a strong candidate for providing an effective antimicrobial nature in human healthcare.

Ultra-small gold nanoclusters assembled on plasma polymer-modified zeolites: a multifunctional nanohybrid with anti-haemorrhagic and anti-inflammatory properties

Hemostatic agents are pivotal for managing clinical and traumatic bleeding during emergency and domestic circumstances. Herein, a novel functional hybrid nanocomposite material consisting of plasma polymer-modified zeolite 13X and ultra-small gold nanoclusters (AuNCs) was fabricated as an efficient hemostatic agent. The surface of zeolite 13X was functionalised with amine groups which served as binding sites for carboxylate terminated AuNCs. Protein corona studies revealed the enhanced adsorption of two proteins, namely, coagulation factors and plasminogen as a result of AuNCs immobilization on the zeolite surface. The immune response studies showed that the hybrid nanocomposites are effective in reducing inflammation, which combined with a greater attachment of vitronectin, may promote wound healing. The hemostatic potential of the nanocomposite could be directly correlated with their immunomodulatory and anti-haemorrhagic properties. Together, the hybrid nanoengineered material developed in this work could provide a new avenue to tackle life-threatening injuries in civilian and other emergencies.

Glutathione-Conjugated Hydrogels: Flexible Vehicles for Personalized Treatment of Bacterial Infections

PURPOSE

Skin and soft tissue infections are increasingly prevalent and often complicated by potentially fatal therapeutic hurdles, such as poor drug perfusion and antibiotic resistance. Delivery vehicles capable of versatile loading may improve local bioavailability and minimize systemic toxicities yet such vehicles are not clinically available. Therefore, we aimed to expand upon the use of glutathione-conjugated poly(ethylene glycol) GSH-PEG hydrogels beyond protein delivery and evaluate the ability to deliver traditional therapeutic molecules.

METHODS

PEG and GSH-PEG hydrogels were prepared using ultraviolet light (UV)-polymerization. Hydrogel loading and release of selected drug candidates was examined using UV-visible spectrometry. Therapeutic molecules and GST-fusion protein loading was examined using UV-visible and fluorescent spectrometry. Efficacy of released meropenem was assessed against meropenem-sensitive and -resistant P. aeruginosa in an agar diffusion bioassay.

RESULTS

For all tested agents, GSH-PEG hydrogels demonstrated time-dependent loading whereas PEG hydrogels did not. GSH-PEG hydrogels released meropenem over 24 h. Co-loading of biologic and traditional therapeutics into a single vehicle was successfully demonstrated. Meropenem-loaded GSH-PEG hydrogels inhibited the growth of meropenem-sensitive and resistant P. aeruginosa isolates.

CONCLUSION

GSH ligands within GSH-PEG hydrogels allow loading and effective delivery of charged therapeutic agents, in addition to biologic therapeutics.

Chitosan-Based Nanocomposite Polymeric Membranes for Water Purification-A Review

During the past few years, researchers have focused their attention on developing innovative nanocomposite polymeric membranes with applications in water purification. Natural and synthetic polymers were considered, and it was proven that chitosan-based materials presented important features. This review presents an overview regarding diverse materials used in developing innovative chitosan-based nanocomposite polymeric membranes for water purification. The first part of the review presents a detailed introduction about chitosan, highlighting the fact that is a biocompatible, biodegradable, low-cost, nontoxic biopolymer, having unique structure and interesting properties, and also antibacterial and antioxidant activities, reasons for using it in water treatment applications. To use chitosan-based materials for developing nanocomposite polymeric membranes for wastewater purification applications must enhance their performance by using different materials. In the second part of the review, the performance's features will be presented as a consequence of adding different nanoparticles, also showing the effect that those nanoparticles could bring on other polymeric membranes. Among these features, pollutant's retention and enhancing thermo-mechanical properties will be mentioned. The focus of the third section of the review will illustrate chitosan-based nanocomposite as polymeric membranes for water purification. Over the last few years, researchers have demonstrated that adsorbent nanocomposite polymeric membranes are powerful, important, and potential instruments in separation or removal of pollutants, such as heavy metals, dyes, and other toxic compounds presented in water systems. Lastly, we conclude this review with a summary of the most important applications of chitosan-based nanocomposite polymeric membranes and their perspectives in water purification.

PEG-crosslinked-chitosan hydrogel films for in situ delivery of Opuntia ficus-indica extract

In the present study, chitosan-based wound dressings loaded with the extract of Opuntia ficus-indica (OPU) were prepared. OPU is known for its capability to accelerate skin injury repair. Chitosan (Ch) was crosslinked with a low molecular weight diepoxy-poly(ethylene glycol) (diePEG), and hydrogel films with different Ch/PEG composition and OPU content were prepared by casting. The occurrence of crosslinking reaction was confirmed by FTIR spectroscopy. FTIR and DSC analysis suggested that ionic interactions occur between chitosan and OPU. Tensile tests evidenced that the crosslinking caused a decrease of Young's modulus, which approaches the value of the human skin modulus. Swelling characteristics, water vapor transmission rate, and release kinetics demonstrated that these films are adequate for the proposed application. Finally, a scratch test on a keratinocytes monolayer showed that the rate of cell migration in the presence of OPU-loaded samples is about 3-fold higher compared to unloaded films, confirming the repairing activity of OPU.

Recent advances of hydrogel-based biomaterials for intervertebral disc tissue treatment: A literature review

Low back pain is an increasingly prevalent symptom mainly associated with intervertebral disc (IVD) degeneration. It is highly correlated with aging, as the nucleus pulposus (NP) dehydrates and annulus fibrosus fissure formatting, which finally results in the IVD herniation and related clinical symptoms. Hydrogels have been drawing increasing attention as the ideal candidates for IVD degeneration because of their unique properties such as biocompatibility, highly tunable mechanical properties, and especially the water absorption and retention ability resembling the normal NP tissue. Numerous innovative hydrogel polymers have been generated in the most recent years. This review article will first briefly describe the anatomy and pathophysiology of IVDs and current therapies with their limitations. Following that, the article introduces the hydrogel materials in the classification of their origins. Next, it reviews the recent hydrogel polymers explored for IVD regeneration and analyses what efforts have been made to overcome the existing limitations. Finally, the challenges and prospects of hydrogel-based treatments for IVD tissue are also discussed. We believe that these novel hydrogel-based strategies may shed light on new possibilities in IVD degeneration disease.

On-demand and tunable dual wavelength release of antibody using light-responsive hydrogels

There has been an increased interest in the use of protein therapeutics, especially antibodies, for the treatment of a variety of diseases due to their high specificity to tissues and biological pathways of interest. However, the use of antibodies can be hindered by physical aggregation, degradation, and diffusion when injected in vivo leading to the need for antibody-releasing depots for the controlled and localized delivery within tissues of interest. Here, we investigated photolabile hydrogel chemistries for creating on-demand and tunable antibody release profiles. Innovative, scalable synthetic procedures were established and applied for fabricating hydrogels with nitrobenzyl (NB) and coumarin (CMR) photolabile crosslinks that responded to clinically relevant doses of long-wavelength UV and short-wavelength visible light. This synthetic procedure includes a route to make a CMR linker possessing two functional handles at the same ring position with water-stable bonds. The photocleavage properties of NB and CMR crosslinked hydrogels were characterized, as well as their potential for translational studies by degradation through pig skin, a good human skin mimic. The mechanism of hydrogel degradation, bulk versus surface eroding, was determined to be dependent on the wavelength of light utilized and the molar absorptivity of the different photolabile linkers, providing a facile means for altering protein release upon hydrogel degradation. Further, the encapsulation and on-demand release of a model monoclonal antibody was demonstrated, highlighting the ability to control antibody release from these hydrogels through the application of light while retaining its bioactivity. In particular, the newly designed CMR hydrogels undergo surface erosion-based protein release using visible light, which is more commonly used clinically. Overall, this work establishes scalable syntheses and relevant pairings of formulation-irradiation conditions for designing on-demand and light-responsive material systems that provide controlled, tunable release of bioactive proteins toward addressing barriers to preclinical translation of light-based materials and ultimately improving therapeutic regimens.

Effects of Electrospun Fibrous Membranes of PolyCaprolactone and Chitosan/Poly(Ethylene Oxide) on Mouse Acute Skin Lesions

Polycaprolactone (PCL) is a synthetic polymer with good mechanical properties that are useful to produce biomaterials of clinical application. It can be successfully combined with chitosan, which enhances the biomaterial properties through the modulation of molecular and cellular mechanisms. The objective of this study was to evaluate the effects of the use of electrospun fibrous membranes consisting of polycaprolactone (PCL) or polycaprolactone coated with chitosan and poly(ethylene oxide) (PCL+CHI/PEO) on mouse skin lesions. Sixty four Black-57 mice were divided into PCL and PCL+CHI/PEO groups. A 1 cm² lesion was made on the animals’ backs, and the membranes were sutured in place. The tissues were extracted on the 3rd, 7th, and 14th days after the lesion. The tissues were analyzed by histology with Hematoxylin and Eosin (H&E) and Sirius Red stains, morphometry, immunohistochemistry, and Western blot. On the 3rd, 6th, and 9th days after the lesion, the PCL+CHI/PEO group showed a higher wound-healing rate (WHR). On the 3 day, the PCL+CHI/PEO group showed a greater amount of inflammatory infiltrate, greater expression of proliferating cell nuclear antigen (PCNA), and smooth muscle actin (α-SMA) (p < 0.05) compared to the PCL group. On the 7th day after the lesion, the PCL+CHI/PEO group showed a greater amount of inflammatory infiltrate, expression of Tumor Necrosis Factor (TNF-α) and PCNA (p < 0.05). In addition, it showed a greater immunolabeling of Monocyte Chemoattractant Protein-1 (MCP-1) and deposition of collagen fibers compared to the PCL group. The PCL+CHI/PEO membrane modulated the increase in the inflammatory infiltrate, the expression of MCP-1, PCNA, and α-SMA in lesions of mice.

Towards advanced wound regeneration

Wound management is a major contributor towards the economic burden placed upon the national health service (NHS), serving as an important target for the development of advanced therapeutic interventions. The economic expenditure of wound care for the NHS exceeds £5 billion per annum, thus presenting a significant opportunity for the introduction of alternative treatments in regards to their approach in tackling the ever increasing prevalence of wound management associated problems. As most wounds typically fall under the acute or chronic category, it is therefore necessary to design a therapeutic intervention capable of effectively resolving the pathologies associated with each problem. Such an intervention should be of increased economic viability and therapeutic effectiveness when compared to standardized treatments, thus helping to alleviate the financial burden imposed upon the NHS. The purpose of this review is to critically analyse the various aspects associated with wound management, detailing the fundamental concepts of dermal regeneration, whilst also providing an evaluation of the different materials and methods that can be utilised to achieve maximal wound regeneration. The primary aspects of this review revolve around the three concepts of antibacterial methodology, enhancement of dermal regeneration and the utilisation of a carrier medium to facilitate the regenerative process. Each aspect is explored, conveying its justifications as a target for dermal regeneration, whilst offering various solutions towards the fulfilment of a therapeutic design that is both effective and financially feasible.

Polyethylene Glycol–Based Nanocerium Improves Healing Responses in Excisional and Incisional Wound Models in Rats

Applications of nanotechnology have gained progressive interest for regeneration of injured wound tissue. The aim of the present study was to evaluate effects of polyethylene glycol (PEG)-based nanocerium on excisional and incisional wound models in rats. For excisional wound healing model, 24 male white Wistar rats were randomized into 4 groups of 6 rats each: control group with creation of wounds and no treatment, PEG group with creation of wounds and dressing the wound with PEG, NanoCer group with application of 1 mL nanocerium on the wound, and PEG/NanoCer group with dressing the wound with PEG-based nanocerium. Wound size was measured on days 6, 9, 12, 15, 18, and 21 postsurgery. For incisional wound healing model, 24 healthy male Wistar rats were randomized into 4 groups of 6 rats each the same way in the excisional wound model. Reduction in wound area, hydroxyproline contents, and biomechanical parameters indicated that there was a significant difference ( P > .05) between PEG/NanoCer and other groups. Biomechanical testing was performed on day 9 postsurgery in the incisional model. Biochemical and quantitative histological studies demonstrated that there was a significant difference ( P > .05) between PEG/NanoCer and other groups. PEG/NanoCer offered potential advantages in wound healing acceleration and improvement through angiogenesis stimulation, fibroblast proliferation, and granulation tissue formation on early days of healing phases. Acceleration in wound repair was associated with earlier wound area reduction and enhanced tensile strength of damaged area by rearrangement of granulation tissue and collagen fibers. PEG-based nanocerium could have therapeutic benefits in wound healing.

Biomaterials and controlled release strategy for epithelial wound healing

The skin and cornea are tissues that provide protective functions. Trauma and other environmental threats often cause injuries, infections and damage to these tissues, where the degree of injury is directly correlated to the recovery time. For example, a superficial skin or corneal wound may recover within days; however, more severe injuries can last up to several months and may leave scarring. Thus, therapeutic strategies have been introduced to enhance the wound healing efficiency and quality. Although the skin and cornea share similar anatomic structures and wound healing process, therapeutic agents and formulations for skin and cornea wound healing differ in accordance with the tissue and wound type. In this review, we describe the anatomy and epithelial wound healing processes of the skin and cornea, and summarize the therapeutic molecules that are beneficial to the respective regeneration process. In addition, biomaterial scaffolds that inherently possess bioactive properties or modified with therapeutic molecules for topical controlled release and enhanced wound healing efficiency are also discussed.

Cellulose Nanofibril Formulations Incorporating a Low-Molecular-Weight Alginate Oligosaccharide Modify Bacterial Biofilm Development

Cellulose nanofibrils (CNFs) from wood pulp are a renewable material possessing advantages for biomedical applications because of their customizable porosity, mechanical strength, translucency, and environmental biodegradability. Here, we investigated the growth of multispecies wound biofilms on CNF formulated as aerogels and films incorporating the low-molecular-weight alginate oligosaccharide OligoG CF-5/20 to evaluate their structural and antimicrobial properties. Overnight microbial cultures were adjusted to 2.8 × 10⁹ colony-forming units (cfu) mL^-1 in Mueller Hinton broth and growth rates of Pseudomonas aeruginosa PAO1 and Staphylococcus aureus 1061A monitored for 24 h in CNF dispersions sterilized by γ-irradiation. Two CNF formulations were prepared (20 g m^-2) with CNF as air-dried films or freeze-dried aerogels, with or without incorporation of an antimicrobial alginate oligosaccharide (OligoG CF-5/20) as a surface coating or bionanocomposite, respectively. The materials were structurally characterized by scanning electron microscopy (SEM) and laser profilometry (LP). The antimicrobial properties of the formulations were assessed using single- and mixed-species biofilms grown on the materials and analyzed using LIVE/DEAD staining with confocal laser scanning microscopy (CLSM) and COMSTAT software. OligoG-CNF suspensions significantly decreased the growth of both bacterial strains at OligoG concentrations >2.58% (P < 0.05). SEM showed that aerogel-OligoG bionanocomposite formulations had a more open three-dimensional structure, whereas LP showed that film formulations coated with OligoG were significantly smoother than untreated films or films incorporating PEG400 as a plasticizer (P < 0.05). CLSM of biofilms grown on films incorporating OligoG demonstrated altered biofilm architecture, with reduced biomass and decreased cell viability. The OligoG-CNF formulations as aerogels or films both inhibited pyocyanin production (P < 0.05). These novel CNF formulations or bionanocomposites were able to modify bacterial growth, biofilm development, and virulence factor production in vitro. These data support the potential of OligoG and CNF bionanocomposites for use in biomedical applications where prevention of infection or biofilm growth is required.

Nanoengineered chlorin e6 conjugated with hydrogel for photodynamic therapy on cancer

The aim of the present study is to fabricate hydrogel as a photosensitizer (PS) for photodynamic therapy. Chlorin e6 (Ce6)-fucoidan/alginates@gellam gum (Ce6-Fu/AL@GG)-based hydrogel was fabricated and characterised in terms of morphology and functional groups. MTT assay was used to check toxicity and also performed scratch assay for wound healing property of Ce6-Fu/AL@GGH. Fourier transform infrared spectroscopy (FT-IR) confirmed the existence of physical interactions between polysaccharides. Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) analysis confirmed a decrease in the thermal stability of the fabricated hydrogel. Scanning electron microscope (SEM) and Transmission electron microscope (TEM) images demonstrated porous matrixes representing homogeneous dispersion of nanoparticles in the hydrogel. Cytotoxicity tests revealed that a decrease in the cell viability occurred in PDT after 48 h treatment. Both Ce6 and laser irradiation induced the HT-29 apoptotic effect that was mediated by intracellular ROS generation and mitochondrial damage. The laser-treated hydrogel was effective in inhibiting HT-29 cell growth. Ce6-Fu/AL@GG hydrogel can be a promising platform for PDT on cancer treatment.

Toward Regeneration of the Heart: Bioengineering Strategies for Immunomodulation

Myocardial Infarction (MI) is the most common cardiovascular disease. An average-sized MI causes the loss of up to 1 billion cardiomyocytes and the adult heart lacks the capacity to replace them. Although post-MI treatment has dramatically improved survival rates over the last few decades, more than 20% of patients affected by MI will subsequently develop heart failure (HF), an incurable condition where the contracting myocardium is transformed into an akinetic, fibrotic scar, unable to meet the body's need for blood supply. Excessive inflammation and persistent immune auto-reactivity have been suggested to contribute to post-MI tissue damage and exacerbate HF development. Two newly emerging fields of biomedical research, immunomodulatory therapies and cardiac bioengineering, provide potential options to target the causative mechanisms underlying HF development. Combining these two fields to develop biomaterials for delivery of immunomodulatory bioactive molecules holds great promise for HF therapy. Specifically, minimally invasive delivery of injectable hydrogels, loaded with bioactive factors with angiogenic, proliferative, anti-apoptotic and immunomodulatory functions, is a promising route for influencing the cascade of immune events post-MI, preventing adverse left ventricular remodeling, and offering protection from early inflammation to fibrosis. Here we provide an updated overview on the main injectable hydrogel systems and bioactive factors that have been tested in animal models with promising results and discuss the challenges to be addressed for accelerating the development of these novel therapeutic strategies.