جستجوی مقالات مرتبط با کلیدواژه « hydrogels » در نشریات گروه « پزشکی »

The skin serves as the main defense barrier, protecting against injuries, and preventing infection and water loss. Consequently, wound healing and skin regeneration are crucial aspects of wound management. A novel hydrogel scaffold was developed by incorporating carboxymethyl cellulose (CMC) and gelatin (Gel) hydrogels cross-linked with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) containing Sphingosine 1-phosphate (S1P). This hydrogel is applied topically to treat acute wounds and is covered with a human acellular amniotic membrane (hAAM) as a secondary dressing. 

The scaffold was subjected to in vitro cell viability, red blood cell hemolysis, blood clotting index, and in vivo assays. Real-time PCR was implemented to verify the expression of genes involved in skin wounds. The physical and chemical properties of the scaffolds were also tested using weight loss, swelling ratio, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and mechanical tensile analysis. 

The synthetic scaffold is biocompatible as evidenced by the high percentage of 3T3 cell viability (127%) after 72 hr. Additionally, excellent hemocompatibility with a low hemolytic effect (2.26%) was observed. Our in vivo wound healing assay demonstrated that CMC/Gel/S1P/hAAM wound dressing led to faster wound healing in treated rats compared to the control group over 14.Also, the mechanical tests showed that the amniotic membrane and the hAAM had very different Young’s modulus and elongation at break values.

This study demonstrates the effectiveness of the CMC/Gel/EDC hydrogel with S1P as a wound dressing. Additionally, hAAM exhibits excellent characteristics as a protective layer for the treatment of acute wounds.

The main cause of mortality in burn patients is infection from burns. Drug-resistant bacteria are the main causes of wound infection, so alternative antibiotic therapies hold significant importance. The objective of this study was to examine the impact of a collagen hydrogel that contains a nanoemulsion of Lavandula essential oil on the heal- ing process of infected burn wounds.

In this experimental study, 20 rats were randomly divided after applying burns with a 10 mm diameter hot plate and infecting the wounds with multidrug-resistant Pseudomonas aeruginosa into four groups, including a positive control, a negative control, the first experiment (collagen hydrogel), and the second experiment (collagen hydrogel containing Lavandula essential oil nanoemulsion). On the 4th, 11th, and 18th days, tissue samples were taken for pathology studies. The important parameters in burn wound healing with hematoxylin and eosin and Masson's trichrome staining meth- ods were investigated and scored according to Abramov’s method.

Based on the pathology findings, experimental groups 1 and 2 compared to the negative and positive control groups were effective in rat infection wound healing. The hydrogel scaffold in the experimental groups increased fibroblasts and an- giogenesis compared to the control groups. Epithelization was noticed only in the hydrogel group containing nanoemulsion.

The study findings suggest that the use of collagen hydrogel with Lavandula essential oil nanoemulsion has potential as a wound dressing. This is because it has the potential to effectively promote healing and act as an antibacterial agent to prevent infections.

Defects and dysfunctions of temporomandibular joint (TMJ) disc are responsible for the majority of TMJ diseases. Current treatments in this matter are usually short-term and only palliative, thus an alternative treatment that offers long-lasting repair is in great demand. In recent years great attempts have been made to prepare an ideal scaffold which best resembles the native TMJ disc in characteristics such as mechanical, physical and biological properties. This narrative review focuses on developments of the recent ten years in fabrication of scaffolds using decellularized tissues, natural and synthetic biomaterials for regeneration of TMJ disc and compared their properties. PubMed and Google Scholar databases were searched using the following keywords (“TMJ” OR “temporomandibular joint” OR “TMD” OR “temporomandibular disease”) AND (“scaffold” OR “hydrogels”). Randomized controlled trials, randomized clinical trials, case-controls, case reports, and animal studies were included. Comments, systematic reviews, meta-analyses, and non-English papers were excluded. The study concluded that hybrid scaffolds have exhibited favorable cell attachment and proliferation. Synthetic scaffolds have shown promise in providing better control over structural properties; however, additional processes are often required to provide biomimetic cell signaling. While there is still much to learn about the ideal scaffold for TMJ disc regeneration, both natural and synthetic scaffolds have shown promise in achieving the functional, structural, biological, and mechanical properties of a native TMJ disc.

Characterized by insulin insufficiency due to irreversible pancreas defects, type 1 diabetes is traditionally managed by regular insulin supplementation. Recently, tissue regenerative technology coupled with advanced-level surgical intervention has created hope for a cure. Research in this direction started with replacing defective pancreas with healthy ones. However, the strategy met showed limited success. Presently, extensive work is being conducted to replace the damaged β cells with healthy ones and create insulin-producing cells from stem cells. This study reviews various research strategies used to replace or regenerate β cells for curing diabetes.

The literature survey was done on PubMed and Google Scholar until June 2023. The keywords used were “type 1 diabetes,” “cure,” “techniques,” “islet transplantation,” “encapsulation of β cells,” and “stem cells,” etc. Full-length research and review articles were used as the basis for the preparation of the manuscript. Papers describing the basic features and rationale supporting the development of technologies were included, whereas clinical aspects and case studies were excluded.

Mainly, three important approaches were discussed. Treatment involves transplantation of whole organ (pancreas), islet, and stem cells derived β progenitor cells. A brief discussion was included for each technique, such as the extraction of β cells and generation of insulin-producing cells from stem cells, along with the essential findings obtained from each approach.

The review demonstrated various strategies researchers have undertaken to find a cure for type 1 diabetes in terms of insulin independence.

As the repair capacity of the nervous system is low, stem cell therapy is a trend for replacement therapy. Dental pulp stem cells (DPSCs) have the potential to differentiate into many tissues, such as neurons. Harmine (7-methoxy-1methyl-9H-pyrido[3,4-b] indole) is an alkaloidal component of medicinal plants with a long history in traditional medicine. Alginate is a biocompatible hydrogel widely used as a biomaterial base in various scaffolds.

This study investigated whether harmine and encapsulation of cells in alginate hydrogel could improve DPSCs differentiation into neural cells.

DPSCs were cultured under standard stem cell culture conditions, then encapsulated in alginate hydrogel, and treated with differentiation medium with and without harmine. After 14 days, cell proliferation and differentiation were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, real-time polymerase chain reaction (RT-PCR), and flow cytometry.

Harmine (5 and 10 M) significantly increased the proliferation and viability of DPSCs compared to the control group in both two-dimensional and three-dimensional culture systems (P < 0.05). The expression levels of three neural cell markers (nestin, microtubule-associated protein [MAP-2], and -tubulin III) in DPSCs-derived neural cells cultured in two-dimensional and three-dimensional culture systems were significantly increased in harmine-treated two-dimensionalandthree-dimensional culture systems compared to the control group (P < 0.05).

Either harmine or alginate hydrogel had an accelerating effect on DPSCs differentiation into neural cells. Harmine also increased the proliferation of the cells.

The objective of the current study was to develop a human treated dentin matrix (hTDM) hydrogel for use as a scaffold to allow the controlled release of an antimicrobial agent for regenerative endodontics.

Human extracted teeth were treated via chemical demineralization using ethylene diamine tetra-acetic acid solution to produce hTDM powder. Fourier transform infrared spectroscopy (FTIR) was conducted to determine the functional groups of hTDM, scanning electron microscopy (SEM) was used to define the morphology/particle size of hTDM, and energy dispersive X-ray analysis was performed to identify the superficial apatite groups. Prepared hTDM powder was added to the amoxicillin-clavulanate mixture with a mass ratio of 1:1. Then, the combination was dripped into a 5% (w/v) calcium chloride solution. Antibiotic release profiles were evaluated for 14 days via high performance liquid chromatography (HPLC). Hydrogel degradation properties were studied for 14 days using 10 mL of phosphate buffered saline (PBS). Encapsulation efficiency was determined by HPLC, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of amoxicillin-clavulanate were determined against Enterococcus faecalis (E. faecalis). The antibacterial activity of amoxicillin-clavulanate against E. faecalis was investigated for 14 days via agar diffusion test. Statistical analysis was performed with the Shapiro-Wilk test (P=0.05).

hTDM showed statistically a significant difference for percentage weight change (P=0.1). The encapsulation efficiencies for hTDM hydrogel with antibiotic and hydrogel with antibiotic was 96.08%±0.02 and 94.62%±0.11, respectively. MIC and MBC values of amoxicillin-clavulanate against E. faecalis were 2.4 µg/mL and 9.6 µg/mL, respectively. The antibacterial activity of antibiotic loaded hTDM hydrogels was significantly greater than loaded hydrogels alone by 31% after 4 and 100% at 14 days, respectively (P≤0.001).

This in vitro study showed antibiotic-loaded injectable hTDM hydrogel could be an alternative system to transfer antibiotic-based intracanal medicaments for use in regenerative endodontics.

Periodontal tissues are organized in a complex three-dimensional (3D) architecture, including the alveolar bone, cementum, and a highly aligned periodontal ligament (PDL). Regeneration is difficult due to the complex structure of these tissues. Currently, materials are developing rapidly, among which synthetic polymers and hydrogels have extensive applications. Moreover, techniques have made a spurt of progress. By applying guided tissue regeneration (GTR) to hydrogels and cell sheets and using 3D printing, a scaffold with an elaborate biomimetic structure can be constructed to guide the orientation of fibers. The incorporation of cells and biotic factors improves regeneration. Nevertheless, the current studies lack long-term effect tracking, clinical research, and in-depth mechanistic research. In summary, periodontal tissue engineering still has considerable room for development. The development of materials and techniques and an in-depth study of the mechanism will provide an impetus for periodontal regeneration.

Enzymes are one of the main biocatalysts with various applications in the food industry. Stabilization of enzymes on insoluble carriers is important due to the low reuse, low operational stability, and high cost in applications. The immobility and the type of carrier affect the activity of the immobile enzyme. Hydrogels are three-dimensionally cross-linked macromolecular network structures designed from various polymers. Hydrogels can provide a matrix for an immobile enzyme due to their extraordinary properties such as high water absorbing capacity, carrier of bioactive substances and enzymes, biocompatibility, safety, and biodegradability. Therefore, this study mainly focuses on some enzymes (Lactase, Lipases, Amylases, Pectinase, Protease, Glucose oxidase) that are of special importance in the food industry. These enzymes could be immobilized in the hydrogels constructed of macromolecules such as kappa-carrageenan, chitosan, arabic gum, pectin, alginate, and cellulose. At last, in the preparation of these hydrogels, different enzyme immobilization methods in macromolecular hydrogels, and effect of hydrogels on enzyme activity were discussed.

Inflammatory bone resorption in periodontitis can lead to tooth loss. Systemic administration of bisphosphonates such as risedronate for preventing bone resorption can cause adverse effects. Alginate hydrogel (ALG) and poly (lactic acid-co-glycolic acid) (PLGA) microparticles have been studied as drug delivery systems for sustained release of drugs. Therefore, the release pattern of risedronate from PLGA microparticles embedded with ALG was studied as a drug delivery system for sustained release of the drug, which can be used in local administrations.

Risedronate-containing PLGA microparticles were fabricated using double emulsion solvent evaporation technique. Ionic cross-linking method was used to fabricate risedronate-loaded ALG. Risedronate-containing PLGA microparticles were then coated with ALG. The calibration curve of risedronate was traced to measure encapsulation efficiency (EE) and study the release pattern. Scanning electron microscope (SEM) imaging was carried out, and cell toxicity was examined using MTT assay. Statistical analysis of data was carried out using SPSS ver. 20 software, via one-way ANOVA and Tukey’s tests.  

SEM imaging showed open porosities on ALGs. The mean EE of PLGA microparticles for risedronate was 57.14 ± 3.70%. Risedronate released completely after 72 h from ALG, and the cumulative release was significantly higher (p = 0.000) compared to PLGA microspheres coated with ALG, which demonstrated sustained released of risedronate until day 28. Risedronate-loaded ALG showed a significant decrease in gingival fibroblasts cell viability (p < 0.05).

Alginate-coated PLGA microspheres could release risedronate in a sustained and controlled way and also did not show cell toxicity. Therefore, they seem to be an appropriate system for risedronate delivery in local applications

Self-assembling peptides (SApeptides) have growing applications in tissue engineering and regenerative medicine. The application of SApeptide-based hydrogels depends strongly on their viscoelastic properties. Optimizing the properties is of importance in tuning the characteristics of the hydrogels for a variety of applications.

In this study, we employed statistical modeling, conducted with the response surface methodology (RSM) and particle tracking microrheology, to investigate the effects of self-assembling SPG-178 peptide and added NaCl salt concentrations and milieu type (deionized water or blood serum) on the viscoelastic properties of SPG-178 hydrogels. A central composite RSM model was employed for finding the optimum value of the parameters to achieve the highest storage modulus and the lowest tan δ.

Viscoelastic properties of each sample, including storage modulus, loss modulus, and tan δ, were determined. Storage modulus and tan δ were modeled, accounting for the impact of the SPG-178 peptide and NaCl concentrations and milieu type on the viscoelastic properties. It was found that the SPG-178 hydrogel storage modulus was positively influenced by the SPG-178 peptide concentration and the serum.

A combination of microrheology and RSM is a useful test method for statistical modeling and analysis of rheological behavior of solid-like gels, which could be applied in various biomedical applications such as hemostasis.

Hydrogels are cross-linked polymers with hydrophilic groups which enable them to absorb large amounts of water. Hydrogel based delivery systems have been used for delivery of different types of active pharmaceuticals. Although hydrogels have numerous capability and advantages in drug delivery including biocompatibility, low toxicity and good swelling behavior but depending on chemical moieties of the gel forming polymers and route of administration some limitations would appear in delivery of active pharmaceutical using hydrogel as delivery vehicle. Development of successful hydrogel based delivery system is possible upon knowledge about the hydrogels forming polymers physiochemical properties and understanding the influencing factors which control the swelling behaviors, hydrophilicity, biodegradability, biocompatibility and targetability of the selected polymer. In this review at first classification of the hydrogel with different approaches including chemical moieties, crosslinking agent behaviors and release controller mechanism was performed and limitations arise from each category was described and finally different approaches to overcome each of this limitation was proposed.