Healing Capability Research Articles

Subgingival Use of Air-Polishing Powders: Status of Knowledge: A Systematic Review.

Effective subgingival biofilm removal is crucial for achieving positive and stable outcomes in periodontal therapy, forming an indispensable part of any periodontal treatment approach. The development of air-polishing tools has emerged as a promising alternative to hand and ultrasonic scalers for dental biofilm removal. The objective of this systematic review was to assess existing literature regarding the subgingival use of various types of air-polishing powders, as an effective method of subgingival biofilm control. For this, 55 articles on this subjected were sourced from searched databases and subjected to an evaluation process of their contained information, which was subsequently structured and compiled into this manuscript. The existing literature acknowledges that good subgingival biofilm control is essential for the success of periodontal therapy, including through subgingival air-polishing, as an adjunctive procedure. This approach has the potential to enhance patient comfort during and after subgingival mechanical plaque removal, thereby mitigating damage to periodontal structures. Consequently, it may lead to improved healing capabilities within the periodontal tissues and the formation of a more stable reparative gingival junctional epithelium.

Use of Platelet Rich Plasma in Otolaryngology-Review Article

The process of replacing or regenerating human cells, tissues, or organs to restore or establish normal function is known as REGENERATIVE MEDICINE. It is a brand new, developing field of medicine that deals with the functional repair of tissues or organs damaged by severe trauma or degenerative conditions. Currently, platelet-rich plasma (PRP) and stem cell-based treatments are the two competing technologies that can heal and restore the injured tissues. Platelet-rich plasma (PRP) applications used in new autologous cellular therapeutics have the potential to supplement a range of regenerative medicine therapy regimens [1]. An emerging and effective treatment alternative in musculoskeletal therapy is platelet-rich plasma (PRP) PRP is an autologous plasma preparation that has been enhanced with platelet concentrations above those seen in whole blood ordinarily. High platelet concentration has therapeutic promise because of their ability to give supraphysiologic levels of vital growth factors, which operate as a regenerative stimulus to encourage repair in tissues with poor healing capabilities [2]. A concentration of platelet-rich protein generated from blood that has been spun to remove the red blood cells is known as platelet-rich plasma (PRP), or more accurately autologous conditioned plasma. Despite being advertised to cure a variety of medical ailments, there is conflicting evidence for profit as of 2020, with some evidence supporting usage in some circumstances and opposing use in other. A unique substance that is being employed in several surgical specialities is platelet-rich plasma. The aim of the article is to review the ongoing and prospective utilization of platelet-rich plasma in the field of Otolaryngology [3].

Assessing the Anti-Aging and Wound Healing Capabilities of Etlingera elatior Inflorescence Extract: A Comparison of Three Inflorescence Color Varieties.

Torch ginger, Etlingera elatior, is a Zingiberaceae plant with various red, pink, and white inflorescence. The wound healing potential and anti-aging effects of freeze-dried torch ginger inflorescence extracts (FTIEs) from three varieties were compared. The red FTIE had the highest content of phenolic, flavonoid, caffeoylquinic acid, and chlorogenic acid, followed by the white and pink FTIE. Consistent with the chemical constituents, the red FTIE demonstrated the greatest capacities for free radical scavenging, anti-tyrosinase, and anti-collagenase activity, followed by the white and pink FTIE. In cell-based studies, FTIEs displayed cytotoxicity to B16F10 melanoma cells, with the red FTIE showing the greatest activity (LC50 of 115.5 μg/mL). In contrast, the pink and the white FTIEs had less cytotoxicity impact. Nonetheless, at 1000 μg/mL, all three FTIE variants were safe on L929 fibroblasts or RAW 264.7 monocyte cells. White FTIE (500 μg/mL) exhibited the highest activity in stimulating collagen production and the greatest impact on cell migration, whereas the pink and red FTIE had a lesser effect. All FTIEs slightly suppressed the pro-inflammatory cytokines produced by lipopolysaccharide-stimulated monocytes, with no significant variation between FTIE variants. In conclusion, all FTIEs revealed promising potential for anti-aging cosmeceuticals and wound care products at specific concentrations.

Bioinspired Hemostatic and Anti‐Infective Armor for Wound Healing Assisted by Metal‐Phenol‐Polyamine System

AbstractHemostatic materials facilitate rapid hemostasis and significantly mitigate the potential of fatal hemorrhage in civilian and military traumas. However, most existing hemostatic materials are limited in material‐dependent forms and fail to integrate multifunctionality, thus constraining their versatility for differing settings and wound healing capacity. Herein, a facile, versatile armor strategy is proposed to endow various biomaterials with rapid hemostasis, infection prevention, and tissue healing capabilities. The armor is fabricated on the surface of substrates first through chemical cross‐linking of adhesive catechol (phenol) and collagen (polyamine) inspired by insect sclerotization, followed by zinc ions (Zn2+) chelation based on mussel‐inspired metal‐phenol coordination chemistry, referred to “metal‐phenol‐polyamine system”. This armor facilitates clot formation by promoting platelet aggregation and activating both intrinsic and extrinsic coagulation pathways. Moreover, the integrated Zn2+ endows the armor with potent antibacterial properties against both Gram‐positive and Gram‐negative bacteria. Consequently, this strategy armors a hemostatic sponge that effectively controls bleeding in rabbit hemorrhage models and successfully facilitates the complete healing of epidermal traumas in rats within 14 days. This metal‐phenol‐polyamine system‐assisted armor provides a potential and universal strategy for efficient hemostasis and wound healing.

Nanoparticles fabricated from the bioactive tilapia scale collagen for wound healing: Experimental approach.

The creation of innovative wound-healing nanomaterials based on natural compounds emerges as a top research goal. This research aimed to create a gel containing collagen nanoparticles and evaluate its therapeutic potential for skin lesions. Collagen nanoparticles were produced from fish scales using desolvation techniques. Using SDS PAGE electrophoresis, Fourier transform infrared spectroscopy (FTIR) as well as the structure of the isolated collagen and its similarities to collagen type 1 were identified. The surface morphology of the isolated collagen and its reformulation into nanoparticles were examined using transmission and scanning electron microscopy. A Zeta sizer was used to examine the size, zeta potential, and distribution of the synthesized collagen nanoparticles. The cytotoxicity of the nanomaterials was investigated and an experimental model was used to evaluate the wound healing capability. The overall collagen output from Tilapia fish scales was 42%. Electrophoretic patterns revealed that the isolated collagen included a unique protein with chain bands of 126-132 kDa and an elevated beta band of 255 kDa. When compared to the isolated collagen, the collagen nanoparticles' FTIR results revealed a significant drop in the amide II (42% decrease) and amide III (32% decrease) band intensities. According to SEM analysis, the generated collagen nanoparticles ranged in size from 100 to 350 nm, with an average diameter of 182 nm determined by the zeta sizer. The produced collagen nanoparticles were polydispersed in nature and had an equivalent average zeta potential of -17.7 mV. Cytotoxicity study showed that, when treating fibroblast cells with collagen nanoparticle concentrations, very mild morphological alterations were detected after human skin fibroblasts were treated with collagen nanoparticles 32 μg/ml for 24 hours, as higher concentrations of collagen nanoparticles caused cell detachment. Macroscopical and histological investigations proved that the fabricated fish scale collagen nanoparticles promoted the healing process in comparison to the saline group.

G-Quadruplex/Hemin DNAzyme-Functionalized Silver Nanoclusters with Synergistic Antibacterial and Wound Healing Capabilities for Infected Wound Management.

Systematic management of infected wounds requires simultaneous antiinfection and wound healing, which has become the current treatment dilemma. Recently, a multifunctional silver nanoclusters (AgNCs)-based hydrogel dressing to meet these demands is developed. Here a diblock DNA with a cytosine-rich fragment (as AgNCs template) and a guanine-rich fragment (to form G-quadruplex/hemin DNAzyme, termed G4/hemin) is designed, for G4/hemin functionalization of AgNCs. Inside bacteria, G4/hemin can not only accelerate the oxidative release of Ag+ from AgNCs but also generate reactive oxygen species (ROS) via catalase- and peroxidase-mimic activities, which enhance the antibacterial effect. On the other hand, the AgNCs exhibit robust anti-inflammatory and antioxidative activities to switch M1 macrophages into M2 phenotype, which promotes wound healing. Moreover, the hemin is released to upregulate the heme oxygenase-1, an intracellular enzyme that can relieve oxidative stress, which significantly alleviates the cytotoxicity of silver. As a result, such silver-based dressing achieves potent therapeutic efficacy on infected wounds with excellent biosafety.

In situ photo-crosslinkable hyaluronic acid-based hydrogel embedded with GHK peptide nanofibers for bioactive wound healing

A versatile hydrogel was developed for enhancing bioactive wound healing by introducing the amphiphilic GHK peptide (GHK-C16) into a photo-crosslinkable tyramine-modified hyaluronic acid (HA-Ty). GHK-C16 self-assembled into GHK nanofibers (GHK NF) in HA-Ty solution, which underwent in situ gelation after the wound area was filled with precursor solution. Blue light irradiation (460–490 nm), with riboflavin phosphate as a photoinitiator, was used to trigger crosslinking, which enhanced the stability of the highly degradable hyaluronic acid and enabled sustained release of the nanostructured GHK derivatives. The hydrogels provided a microenvironment that promoted the proliferation of dermal fibroblasts and the activation of cytokines, leading to reduced inflammation and increased collagen expression during wound healing. The complexation of Cu2+ into GHK nanofibers resulted in superior wound healing capabilities compared with non-lipidated GHK peptide with a comparable level of growth factor (EGF). Additionally, nanostructured Cu-GHK improved angiogenesis through vascular endothelial growth factor (VEGF) activation, which exerted a synergistic therapeutic effect. Furthermore, in vivo wound healing experiments revealed that the Cu-GHK NF/HA-Ty hydrogel accelerated wound healing through densely packed remodeled collagen in the dermis and promoting the growth of denser fibroblasts. HA-Ty hydrogels incorporating GHK NF also possessed improved mechanical properties and a faster wound healing rate, making them suitable for advanced bioactive wound healing applications. Statement of significanceBy combining photo-crosslinkable tyramine-modified hyaluronic acid with self-assembled Cu-GHK-C16 peptide nanofibers (Cu-GHK NF), the Cu-GHK NF/HA-Ty hydrogel offers remarkable advantages over conventional non-structured Cu-GHK for wound healing. It enhances cell proliferation, migration, and collagen remodeling—critical factors in tissue regeneration. The incorporation of GHK nanofibers complexed with copper ions imparts potent anti-inflammatory effects, promoting cytokine activation and angiogenesis during wound healing. The Cu-GHK NF/hydrogel's unique properties, including in situ photo-crosslinking, ensure high customization and potency in tissue regeneration, providing a cost-effective alternative to growth factors. In vivo experiments further validate its efficacy, demonstrating significant wound closure, collagen remodeling, and increased fibroblast density. Overall, the Cu-GHK NF/HA-Ty hydrogel represents an advanced therapeutic option for wound healing applications.

Design of Core-Shell Polylactic Acid (PLA) electrospun nanofibers as potential healing carriers

This study intends to maximize the encapsulation rate of healing carriers in core-shell nanofibers to augment the healing capabilities of the nanofibers in laminated composites synthesized via coaxial electrospinning. Core-shell nanofibers fabricated at a high core flow rate yielded defective fibers due to an insufficiency of shell solution to encapsulate the core solution being ejected from the syringe. Hence, a core-to-shell flow rate of 6.7:1 was identified to be optimal with an encapsulation content of over 50% without affecting its morphology. Thermogravimetric and spectral analysis of the healing NF showed the degradation of each constituent and their respective peaks, confirming the presence of the core solution without any chemical reaction with the PLA shell wall. Release of healing agents was observed under SEM, and the self-healing traits of the nanofibers were studied by subjecting them to repeated loadings under tension with significant strength retention without failure after four load cycles making these nanofibers highly valuable as a secondary reinforcement in polymer composites due to the nanofibers’ toughening and healing capabilities.

Polymeric Chitosan/Poly (Vinyl Alcohol) Hybrid Doped with Zinc Oxide Nanoparticles Synthesized and Characterized Using the Electrospun Method

Background:Because of their portability and flexibility in altering surface properties, nanofibers have attracted more attention in recent years, particularly in biological applications. The development of affordable antibacterial base agents for wound healing capabilities and other medical technologies is still in high demand. Porosity, ease of forming into different sizes, and high surface area are just a few of the benefits of nanofibers.Materials and Methods:A 90% deacetylated (average 200,000 MW) poly(vinyl alcohol) chitosan with a life of 72000 MW was bought.Results:Through the samples of the electronic scanner, electrospinning rates, flow of 0.6 ml / sec, voltage of 10 kV, distance between the collector and the needle of 8 cm, and the ratio of PVA / CS / ZnO to the polymer with the addition of nanoparticles ratio 0.4% 65 / 35.Conclusion:In this study, the nanofiber compound PVA / CS / ZnO proved to have medical and biological compatibility. There is no toxicity in this compound. It has therapeutic properties against microbes and is good in healing wounds, as in previous studies

Comparison of Antimicrobial Activity of Injectable Platelet-Rich Fibrin (i-PRF) and Leukocyte and Platelet-Rich Fibrin (l-PRF) Against Oral Microbes: An In Vitro Study.

Aim Injectable platelet-rich fibrin (i-PRF) and leukocyte and platelet-rich fibrin (l-PRF) are both blood-derived products used in regenerative medicine and dentistry. They contain platelets, growth factors, and leukocytes, which can have antimicrobial properties to some extent, but their primary purpose is tissue regeneration and wound healing. i-PRF and l-PRF may have some indirect antimicrobial properties due to their composition and ability to enhance tissue healing and immune responses, and they are primarily used in dentistry for their regenerative and wound healing capabilities rather than as standalone antimicrobial agents. This study aims to compare the anti-microbial activity of i-PRF and l-PRF against oral microbes. Methodology This study included 30 patients who were selected using G*Power software version 3.1 (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany) calculation with the population size. The plaque samples were collected from the subjects using area-specific Gracey curettes used for scaling and root planing to remove plaque and calculus from the teeth and root surfaces. The collected plaque samples were transferred to a tube containing 5 ml of saline (sterile saltwater). The purpose of using saline is to preserve the microbial content of the plaque sample without altering the microbial composition. To obtain a uniform solution, the samples in the saline-containing tube were vortexed for 5 minutes. After vertexing, a small amount of the suspension (0.1 ml) was taken for further analysis. The 0.1 ml suspension was used to plate blood agar using the streak method. A loop or needle is used to streak the sample back and forth across the surface of the agar, leading to the dilution and separation of the bacteria. Results Results state that i-PRF has a maximum zone of inhibition (2.19±0.47 mm) when compared with metronidazole (0.14±0.09 mm). It can be stated that platelet concentrates demonstrate better antimicrobial activity due to their higher oxygen metabolites which help in the aggregation and internalization of microorganisms, which enhances the clearance of pathogens from the bloodstream. Paired t-test has been used for the comparison between the two groups, and the p-value is >0.05 stating that the difference is statistically significant. Conclusion The present study states that i-PRF demonstrated better antimicrobial efficacy as compared to l-PRF. Hence, i-PRF helps in reducing microbial load at the periodontally infected sites when compared with l-PRF.

Indications of Platelet-Rich Plasma (PRP) in Dermatology

Introduction: PRP is an autologous serum containing high concentrations of platelets and growth factors. It is used in dermatology for a variety of purposes, including hair growth, skin renewal, the removal of acne scars, dermal augmentation, and the treatment of striae distensae. The origins of PRP trace back to the 1970s, originating within the field of hematology as a treatment for patients grappling with thrombocytopenia. The subsequent decades, specifically the 1980s and 1990s, witnessed the integration of PRP into surgical procedures, notably in maxillofacial and plastic surgeries. The rationale underlying the employment and therapeutic potential of a concentrated platelet solution hinges upon their remarkable ability to furnish elevated levels of vital growth factors, thus instigating a regenerative impetus that facilitates repair in tissues characterized by limited innate healing capabilities. This comprehensive review delves into the multifaceted facets of PRP, encompassing mechanisms of action, prevailing indications, existing clinical substantiation, safety considerations, and the burgeoning spectrum of potential applications within the domain of skin condition treatments.
 Aim of the study: To review the current literature on the use of PRP in the field of dermatology
 Materials and Methods: We reviewed the literature available in PubMed, using the key words “platelet rich plasma”, “prp”, “autologous platelet rich plasma”, “alopecia”, “anti-aging”
 Results: PRP has a lot of potential in dermatology and its therapeutic uses are growing. Future research should standardize PRP therapy procedures for particular reasons.
 Summary: The versatile action of PRP has made it the subject of intense research. However, the reports in the literature to date on its use require further studies on larger groups of people to confirm its effects.

Evaluation of healable epoxy matrices as covalent adaptive networks in uniaxial compression

Vitrimers provide dynamic bonding that can allow a degree of self-healing capability in cross-linked resins. A commercial amine-cured epoxy resin, Prime 27, showed a compressive yield stress, measured in compression, of 88 ± 2 MPa and a compression modulus of 3.41 ± 0.03 GPa. This base resin was modified by incorporating various proportions of two commercial vitrimers, either Thioplast EPS35 (an aliphatic epoxy-terminated polysulfide) or Vitrimax T130 (an imine-cured DGEBA epoxy resin). The addition of increasing amounts of Thioplast EPS35 into the resin led to a rapid drop in the glass transition temperature of the matrices and also a reduction in compressive performance. After an initial test in quasi-static, uniaxial compression, samples containing vitrimers were heated for 1 h at 100 °C and then subjected to a second compression test; all of the matrices loaded with Thioplast EPS35 were able to recover their full initial compression performance. Addition of increasing amounts of Vitrimax T130 to the same commercial epoxy resin did not cause any change in its glass transition temperature. However, after initial compression testing, followed by heating (1 h at 100 °C), only the formulation containing 40 wt% Vitrimax T130-loaded matrix regained its full initial compressive performance. Optimal results in terms of healing capability, measured as the recovery of the initial compression performance during a second identical test, following a heating step, were achieved by incorporating 10 wt% of EPS35 or 40 wt% Vitrimax T130, with little to no drop in glass transition temperature. For these selected formulations, the incorporation of 10% Thioplast EPS35 in Prime 27 gave a yield stress of 83 ± 2 MPa and a compression modulus of 3.13 ± 0.02 GPa, while the addition of 40% Vitrimax T130 gave a yield stress of 79 ± 2 MPa and a compression modulus of 3.30 ± 0.02 GPa.

Optimizing postbiotic production through solid-state fermentation with Bacillus amyloliquefaciens J and Lactiplantibacillus plantarum SN4 enhances antibacterial, antioxidant, and anti-inflammatory activities.

Postbiotics are an emerging research interest in recent years and are fairly advanced compared to prebiotics and probiotics. The composition and function of postbiotics are closely related to fermentation conditions. In this study, we developed a solid-state fermentation preparation method for postbiotics with antimicrobial, antioxidant, and anti-inflammatory activities. The antibacterial activity was improved 3.62 times compared to initial fermentation conditions by using optimization techniques such as single factor experiments, Plackett-Burman design (PBD), steepest ascent method (SAM), and central composite design (CCD) methods. The optimized conditions were carried out with an initial water content of 50% for 8 days at 37°C and fermentation strains of Bacillus amyloliquefaciens J and Lactiplantibacillus plantarum SN4 at a ratio of 1:1 with a total inoculum size of 8%. The optimized SSF medium content ratios of peptide powder, wheat bran, corn flour, and soybean meal were 4, 37.4, 30, and 28.6%, respectively. Under these optimized conditions, postbiotics with a concentration of 25 mg/mL showed significant broad-spectrum antibacterial capabilities against Escherichia coli, Salmonella, and Staphylococcus aureus and strong antioxidant activity against ABTS, DPPH, and OH radicals. Moreover, the optimized postbiotics exhibited good anti-inflammatory ability for reducing nitric oxide (NO) secretion in RAW 264.7 macrophage cells in response to LPS-induced inflammation. Furthermore, the postbiotics significantly improved intestinal epithelial wound healing capabilities after mechanical injury, such as cell scratches in IPEC-J2 cells (p < 0.05). In brief, we developed postbiotics through optimized solid-state fermentation with potential benefits for gut health. Therefore, our findings suggested that the novel postbiotics could be used as potential functional food products for improving body health.

Tea polyphenols (TPP) as a promising wound healing agent: TPP exerts multiple and distinct mechanisms at different phases of wound healing in a mouse model

Polyphenols have been widely used to treat various chronic skin diseases because they are beneficial in wound healing and show anti-inflammatory effects, however, the mechanism of action remains ambiguous. Previously, we reported the wound healing capability of tea polyphenols (TPP), the major functional component of tea, in vivo. The current study aimed to address the mechanisms of TPP in wound healing during different phases (inflammation, proliferation and remodeling). During the inflammation phase, TPP reduced the production of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and inhibited infiltration of neutrophils; during the proliferation phase, TPP promoted the expression of growth factor VEGF-A, which can promote vascular endothelial cell division and induce angiogenesis; TPP improved the morphology of the wound and restored the ratio of type III/I collagens during the remodeling phase, as determined by Masson-trichrome staining and Sirius red staining assays. By tracking the changes in the wound area, TPP and recombinant human epidermal growth factor (rhEGF), rather than povidone-iodine (PVP-I), were able to promote wound healing. These results suggest that TPP plays a pivotal role in all the key stages of wound healing and displays distinct mechanisms from rhEGF, suggesting clinical significance for the future application of TPP as a natural wound healing agent.

Low-glucose culture environment can enhance the wound healing capability of diabetic adipose-derived stem cells

BackgroundApplication of autologous adipose-derived stem cells (ASC) for diabetic chronic wounds has become an emerging treatment option. However, ASCs from diabetic individuals showed impaired cell function and suboptimal wound healing effects. We proposed that adopting a low-glucose level in the culture medium for diabetic ASCs may restore their pro-healing capabilities.MethodsASCs from diabetic humans and mice were retrieved and cultured in high-glucose (HG, 4.5 g/L) or low-glucose (LG, 1.0 g/L) conditions. Cell characteristics and functions were investigated in vitro. Moreover, we applied diabetic murine ASCs cultured in HG or LG condition to a wound healing model in diabetic mice to compare their healing capabilities in vivo.ResultsHuman ASCs exhibited decreased cell proliferation and migration with enhanced senescence when cultured in HG condition in vitro. Similar findings were noted in ASCs derived from diabetic mice. The inferior cellular functions could be partially recovered when they were cultured in LG condition. In the animal study, wounds healed faster when treated with HG- or LG-cultured diabetic ASCs relative to the control group. Moreover, higher collagen density, more angiogenesis and cellular retention of applied ASCs were found in wound tissues treated with diabetic ASCs cultured in LG condition.ConclusionsIn line with the literature, our study showed that a diabetic milieu exerts an adverse effect on ASCs. Adopting LG culture condition is a simple and effective approach to enhance the wound healing capabilities of diabetic ASCs, which is valuable for the clinical application of autologous ASCs from diabetic patients.

Cementitious materials with biological additive for enhanced durability in marine environment

AbstractConcrete structures suffer from cracking that leads to deterioration and shortening of service life. This is very critical for underwater structures, i.e., immersed bridge piles, immersed tunnel or submerged floating tunnels, which are consistently susceptible to ingress of harmful ions (chloride, sulphate and carbonate ions). Autonomous healing of concrete cracks can be beneficial to assure durability performance during the service life. In this context the paper presents a preliminary experimental activity carried out to study the self‐healing capacity of cementitious composites in marine environment. Four series of paste samples are prepared to evaluate the autonomous healing capabilities, achieved through biotic and abiotic additions. The experimental campaign is articulated in four phases, such as: specimen preparation; tests in compression; immersion in water; crack healing evaluation. The specimen performances are examined and compared in terms of mechanical strength and crack width healing over time. Results highlight the efficiency of the technology for crack healing.

An Investigation of the Healing Efficiency of Epoxy Vitrimer Composites Based on Zn2+ Catalyst.

The need to recycle carbon-fibre-reinforced composite polymers (CFRP) has grown significantly to reduce the environmental impact generated by their production. To meet this need, thermoreversible epoxy matrices have been developed in recent years. This study investigates the performance of an epoxy vitrimer made by introducing a metal catalyst (Zn2+) and its carbon fibre composites, focusing on the healing capability of the system. The dynamic crosslinking networks endow vitrimers with interesting rheological behaviour; the capability of the formulated resin (AV-5) has been assessed by creep tests. The analysis showed increased molecular mobility above a topology freezing temperature (Tv). However, the reinforcement phase inhibits the flow capability, reducing the flow. The fracture behaviour of CFRP made with the vitrimeric resin has been investigated by Mode I and Mode II tests and compared with the conventional system. The repairability of the vitrimeric CFRP has been investigated by attempting to recover the delaminated samples, which yielded unsatisfactory results. Moreover, the healing efficiency of the modified epoxy composites has been assessed using the vitrimer as an adhesive layer. The joints were able to recover about 84% of the lap shear strength of the pristine system.

Composite Hydrogels with Embedded Silver Nanoparticles and Ibuprofen as Wound Dressing.

The wound healing process is often slowed down as a result of complications from bacterial infections and inflammatory reactions. Therefore, it is necessary to develop dressings with fast antibacterial and anti-inflammatory activity that shorten the wound healing period by promoting cell migration and proliferation. Chitosan (CS)-based hydrogels have been widely studied for their antibacterial and wound healing capabilities. Herein, we developed a composite hydrogel based on CS and PVA embedding silver nanoparticles (AgNPs) with antibacterial properties and ibuprofen (Ib) as an anti-inflammatory agent. The hydrogel prepared by double physical cross-linking, with oxalic acid and by freeze-thawing, loaded with 0.225 wt.% AgNPs and 0.264 wt.% Ib, displayed good mechanical properties (compressive modulus = 132 kPa), a high swelling degree and sustained drug delivery (in simulated skin conditions). Moreover, the hydrogel showed strong antibacterial activity against S. aureus and K. pneumoniae due to the embedded AgNPs. In vivo, this hydrogel accelerated the wound regeneration process through the enhanced expression of TNF alpha IP8, by activating downstream cascades and supporting the healing process of inflammation; Cox2, which enhances the migration and proliferation of cells involved in re-epithelization and angiogenesis; MHCII, which promotes immune cooperation between local cells, eliminating dead tissue and controlling infection; the intense expression of Col I as a major marker in the tissue granulation process; and αSMA, which marks the presence of myofibroblasts involved in wound closure and indicates ongoing re-epithelization. The results reveal the potential healing effect of CS/PVA/AgNPs/Ib hydrogels and suggest their potential use as wound dressings.

Life cycle assessment applied to a self-healing elastomer filled with ground tire rubber

In this study, we present the first life cycle assessment (LCA) of a self-healing styrene-butadiene rubber (SBR) used in the production of marine fenders. Results show that a rubber with healing capabilities is not environmentally attractive if it cannot last for the same lifetime as a conventional product due to its lower mechanical performance and higher energy consumption. To overcome these constraints, we added a sustainable filler, ground tire rubber, which improved the mechanical properties of the self-healing SBR (x6 increase in tensile strength). Although this addition involved additional sub-processes, the additional environmental impacts were outweighed by the benefits achieved through improved material performance (28% decrease in global warming potential - GWP and 26% in primary energy demand - PED). This study used primary data on experimental healing efficiencies and healing cycles rather than conservative assumptions, which provides a more representative and trustworthy LCA of self-healing rubbers. Our findings have significant implications for the rubber industry, as self-healing rubbers offer a promising avenue for reducing the environmental impact of synthetic materials.

Human anterior cruciate ligament-derived mesenchymal stem cells for regenerative medicine applications

Background: The anterior cruciate ligament (ACL) has poor healing capabilities and is the most commonly injured knee ligament. Although ACL repair is being highly studied, the current treatment involves reconstructive surgery utilizing autografts or allografts, which have limitations. The use of Mesenchymal Stem Cells (MSCs) as a possible therapeutic option has grown. ACL-derived MSCs are likely to be the best source because studies have shown that target tissue derived stem cells will better differentiate into the target tissue than the stem cells derived from non-target ones. However, the existing literature discusses only the isolation of a mixed population of MSCs. Here we present the isolation, differentiation and characterization of human ACL-derived MSCs according to the International Society for Cellular Therapy (ISCT) criteria.The ACL tissue was enzymatically digested. Separation of MSCs from the crude mixture of cells was then performed by fluorescence activated cell sorting (FACS) analysis. The isolated population were passaged in specific induction medium to differentiate them into adipocyte, osteocytes and chondrocytes. The cells were then further characterized with respect to their growth curve, population doubling time, colony forming ability, anchorage independent growth, and cell surface markers. The cells were finally examined for their tumorigenic potential by cell cycle analysis.Immunoprofiling via FACSs showed an average isolation rate for cells carrying MSCs markers of 5.5%. Cells exhibited spindle-shaped morphology, and immunocytochemistry confirmed the expression of appropriate cell surface markers. The growth curve showed distinct lag and log phase. Over agar assay demonstrated no anchorage independent growth, but clonogenic potential was observed post-culture on plastic Petri dishes. The cells showed a population doubling time of about 1.5 days. Oil Red O, Alizarin Red S, and Alcian Blue staining confirmed adipogenic, osteogenic and chondrogenic differentiation, respectively. Cell cycle analysis displayed more ACL-derived MSCs in G/G phase compared to BMSCs, showing that the isolates were non-tumorigenic. The presence of MSCs within the human ACL was confirmed via ISCT criteria, paving the way for their potential use for future ACL reconstructions. Although BMSCs have been the choice for regenerative purposes, making use of MSCs derived from ACL ligament will cut down the burden of trauma one has to undergo to obtain the Bone Marrow. Moreover, it is more convenient to harvest MSCs from otherwise discarded ACL. Finally, MSCs derived from the target tissue are believed to better differentiate to the ligament tissue than the bone derived MSCs.