The biocompatible hydrogel was fabricated under suitable conditions with natural dextran and polyethylene glycol (PEG) as the reaction materials. The oligomer (Dex-AI) was firstly synthesized with dextran and allylisocyanate (AI). This Dex-AI was then reacted with poly (ethyleneglycoldiacrylate) (PEGDA) under the mass ratio of 4∶6 to get hydrogel (DP) with the maximum water absorption of 810%. This hydrogel was grafted onto the surface of medical catheter via diphenyl ketone treatment under ultraviolet (UV) initiator. The surface contact angle became lower from (97 ± 6.1)° to (25 ± 4.2)° after the catheter surface was grafted with hydrogel DP, which suggests that the catheter possesses super hydrophilicity with hydrogel grafting. The evaluation after they were implanted into ICR rats subcutaneously verified that this catheter had less serious inflammation and possessed better histocompatibility comparing with the untreated medical catheter. Therefore, it could be concluded that hydrogel grafting is a good technology for patients to reduce inflammation due to catheter implantation, esp. for the case of retention in body for a relative long time.
Allyl Compounds ; Animals ; Biocompatible Materials ; Catheters ; Dextrans ; Hydrogel, Polyethylene Glycol Dimethacrylate ; Hydrogels ; Hydrophobic and Hydrophilic Interactions ; Isocyanates ; Polyethylene Glycols ; Rats ; Water

BACKGROUND: Ice cooling vests can cause tissue damage and have no flexibility. Therefore, these two undesirable properties of ice cooling vest were optimized, and the present study was aimed to compare the impact of the optimized ice cooling vest and a commercial paraffin cooling vest on physiological and perceptual strain under controlled conditions. METHODS: For optimizing, hydrogel was used to increase the flexibility and a layer of the ethylene vinyl acetate foam was placed into the inside layer of packs to prevent tissue damage. Then, 15 men with an optimized ice cooling vest, with a commercial paraffin cooling vest, and without a cooling vest performed tests including exercise on a treadmill (speed of 2.8 km/hr and slope of %0) under hot (40℃) and dry (40 %) condition for 60 min. The physiological strain index and skin temperature were measured every 5 and 15 minutes, respectively. The heat strain score index and perceptual strain index were also assessed every 15 minutes. RESULTS: The mean values of the physiological and perceptual indices differed significantly between exercise with and without cooling vests (P < 0.05). However, the difference of the mean values of the indices except the value of the skin temperature during the exercises with the commercial paraffin cooling vest and the optimized ice cooling vest was not significant (P > 0.05). CONCLUSIONS: The optimized ice cooling vest was as effective as the commercial paraffin cooling vest to control the thermal strain. However, ice has a greater latent heat and less production cost.
Exercise ; Hot Temperature ; Humans ; Hydrogel ; Ice ; Male ; Paraffin ; Pliability ; Skin Temperature

BACKGROUND: Despite the development of progressive surgical techniques and antibiotics, osteomyelitis is a big challenge for orthopedic surgeons. The main aim of this study is to fabricate an in situ gelling hydrogel that permits sustained release of antibiotic (for control of infection) and growth factor (for induction of new bone formation) for effective treatment of osteomyelitis. METHODS: An in situ gelling alginate (ALG)/hyaluronic acid (HA) hydrogel containing vancomycin (antibiotic) and bone morphogenetic protein-2 (BMP-2; growth factor) was prepared by simple mixing of ALG/HA/Na₂HPO₄ solution and CaSO₄/vancomycin/BMP-2 solution. The release behaviors of vancomycin and BMP-2, anti-bacterial effect (in vitro); and therapeutic efficiency for osteomyelitis and bone regeneration (in vivo, osteomyelitis rat model) of the vancomycin and BMP-2-incorporated ALG/HA hydrogel were investigated. RESULTS: The gelation time of the ALG/HA hydrogel was controlled into approximately 4 min, which is sufficient time for handling and injection into osteomyelitis lesion. Both vancomycin and BMP-2 were continuously released from the hydrogel for 6 weeks. From the in vitro studies, the ALG/HA hydrogel showed an effective anti-bacterial activity without significant cytotoxicity for 6 weeks. From an in vivo animal study using Sprague-Dawley rats with osteomyelitis in femur as a model animal, it was demonstrated that the ALG/HA hydrogel was effective for suppressing bacteria (Staphylococcus aureus) proliferation at the osteomyelitis lesion and enhancing bone regeneration without additional bone grafts. CONCLUSIONS: From the results, we suggest that the in situ gelling ALG/HA hydrogel containing vancomycin and BMP-2 can be a feasible therapeutic tool to treat osteomyelitis.
Animals ; Anti-Bacterial Agents ; Bacteria ; Bone Regeneration ; Femur ; Hydrogel ; In Vitro Techniques ; Orthopedics ; Osteomyelitis ; Rats ; Rats, Sprague-Dawley ; Surgeons ; Transplants ; Vancomycin

Polyacrylamide hydrogel (PAAG) was developed in the 1980s as an injectable filler for breast augmentation and tissue contour improvement, but its potential risk for oncogenesis and the frequent occurrence of chronic complications after injections led to the prohibition of its further use as an injectable material. Although breast augmentation with PAAG injections was mostly performed in China and Eastern Europe, the migration of patients and long-term complications of the procedure made it a global concern. Herein, we describe the case of a 49-year-old woman who immigrated to Korea after undergoing breast augmentation via PAAG injection in China, and complained of persistent mastodynia and retraction of both breasts. Surgical treatment was undertaken, along with removal of the PAAG and total capsulectomy of the fibrous capsule containing the gel through an inframammary fold incision. We share our experience of diagnosing and treating this case, and present a literature review.
Breast ; Carcinogenesis ; China ; Europe, Eastern ; Female ; Humans ; Hydrogel ; Korea ; Mastodynia ; Middle Aged ; Pregnancy-Associated alpha 2-Macroglobulins

The removal of fillers used for soft-tissue augmentation is an issue of concern, as the possible need for extensive surgery to remove fillers deters their use by many surgeons. Several studies have demonstrated the safety and efficacy of polyacrylamide hydrogel (Aquamid) gel, but to date no report has described its removal after 10 years. Here, we report a case of Aquamid removal. A 33-year-old woman, who had undergone forehead augmentation 12 years previously with an Aquamid injection, visited the department of plastic and reconstructive surgery of our medical center due to a severe forehead contour irregularity. Removal of 20 mL of excess gel was performed by direct incision and squeezing under local anesthesia. Our experience shows that Aquamid removal is possible, but should be performed with appropriate surgical precautions.
Adult ; Anesthesia, Local ; Dermal Fillers ; Female ; Forehead ; Humans ; Hydrogel ; Plastics ; Surgeons

BACKGROUND: Currently, dermal fillers need to be 25 µm or larger to reduce in vivo degradation by macrophages. However, the large size of fillers may cause side effects, including interruption of blood flow and nodule formation. Therefore, using rats, we tested a polycaprolactone copolymer hydrogel with nanoscale particles that could maintain a low in vivo degradation rate. METHODS: Thirty-six 6-week-old Sprague-Dawley rats were divided into group A (normal saline), group B (polycaprolactone microsphere filler), and group C (polycaprolactone copolymer nanosphere hydrogel). The corresponding materials were injected into the dermal layer of the scalp of the rats. At 4, 8, and 12 weeks after injection, blood biochemical and kidney and liver histological analyses were performed. Tissues were examined using hematoxylin-eosin staining to observe tissue infiltration of materials. Collagen formation in the dermal tissue of the scalp was observed with Masson trichrome staining and the collagen content was quantified using a soluble collagen assay kit. RESULTS: The histologic examination for organ infiltration showed no abnormal findings. All blood test results were within the normal ranges. The amount of collagen at 12 weeks increased by 1.22 mg/g in group C and by 0.6 mg/g in group B. CONCLUSIONS: The results reveal that the nanosphere complex near the injection site induced collagen formation. Regardless of the sphere size, aggregation of the copolymer prevented macrophage phagocytosis. The polycaprolactone copolymer nanosphere hydrogel was effective for more than 3 months when injected in the scalp dermal tissue of Sprague-Dawley rats and can be used safely.
Animals ; Collagen ; Dermal Fillers ; Hematologic Tests ; Hydrogel ; Kidney ; Liver ; Macrophages ; Microspheres ; Nanospheres ; Phagocytosis ; Rats ; Rats, Sprague-Dawley ; Reference Values ; Scalp

BACKGROUND: Reconstruction of large eyelid defects remains challenging due to the lack of suitable eyelid tarsus tissue substitutes. We aimed to evaluate a novel bioengineered chitosan scaffold for use as an eyelid tarsus substitute.METHODS: Three-dimensional macroporous chitosan hydrogel scaffold were produced via cryogelation with specific biomechanical properties designed to directly match characteristics of native eyelid tarsus tissue. Scaffolds were characterized by confocal microscopy and tensile mechanical testing. To optimise biocompatibility, human eyelid skin fibroblasts were cultured from biopsy-sized samples of fresh eyelid skin. Immunological and gene expression analysis including specific fibroblast-specific markers were used to determine the rate of fibroblast de-differentiation in vitro and characterize cells cultured. Eyelid skin fibroblasts were then cultured over the chitosan scaffolds and the resultant adhesion and growth of cells were characterized using immunocytochemical staining.RESULTS: The chitosan scaffolds were shown to support the attachment and proliferation of NIH 3T3 mouse fibroblasts and human orbital skin fibroblasts in vitro. Our novel bioengineered chitosan scaffold has demonstrated biomechanical compatibility and has the ability to support human eyelid skin fibroblast growth and proliferation.CONCLUSIONS: This bioengineered tissue has the potential to be used as a tarsus substitute during eyelid reconstruction, offering the opportunity to pre-seed the patient's own cells and represents a truly personalised approach to tissue engineering.
Animals ; Ankle ; Chitosan ; Cryogels ; Eyelids ; Fibroblasts ; Gene Expression ; Humans ; Hydrogel ; In Vitro Techniques ; Mice ; Microscopy, Confocal ; Orbit ; Skin ; Tissue Engineering

STUDY DESIGN: Prospective pilot study OBJECTIVES: The efficacy and safety of ‘PF-72’ for management of postoperative acute pain through a mixed ‘PF-72’ and 0.75% ropivacaine hydrochloride solution in patients with posterior spine surgery was evaluated as ‘0.75% ropivacaine’ and ‘untreated’ controls. SUMMARY OF LITERATURE REVIEW: Postoperative acute pain is major surgical side effect that lead to the deterioration of the quality of life. Traditional pain control results in variable side effects, and multimodal pain management has been recommended as an alternative. Local anesthetics is a short-acting time lower than 12 hours. There is controversy about the efficiency and stability of thermoreactive hydrogel products as a drug delivery system. MATERIALS AND METHODS: Patients scheduled for posterior spine surgery were enrolled by the inclusion criteria. In the treated group, PF-72 and ropivacaine mixture was injected to the surgical wound before closure. In control group 1, only 0.75% ropivacaine hydrochloride was injected. In the control group 2, the surgical site was without injection. Ten patients were randomly assigned to each group and standardized drugs for pain control were applied postoperatively and rescue regimens were applied when necessary. Postoperative pain score and the cumulative area under the curve (AUC) of pain score were compared. The percentage of subjects who were painless (pain score ≤ 3) was examined at each observation point. The first time of injection and the total dose of the rescue regimen were examined. Postoperative nausea and vomiting (PONV) were also evaluated. RESULTS: There was no significant difference in demographic data. The sum AUC of pain scores in the treated group was significantly lower than that in the control group 1 and 2 at all observation times. The proportion of painless patients was significantly higher in the treated group than in the control group 2. There was no significant difference between the first administration time and the total usage of the rescue regimen, and the percentage of patients with PONV at all time points. There was no statistically significant difference in the incidence of adverse events. CONCLUSIONS: PF-72 and ropivacaine mixture showed significant effects for pain management up to 72 hours postoperatively for the patients who underwent posterior spinal surgery without fatal complications.
Acute Pain ; Anesthetics, Local ; Area Under Curve ; Drug Delivery Systems ; Humans ; Hydrogel ; Incidence ; Pain Management ; Pain, Postoperative ; Pilot Projects ; Postoperative Nausea and Vomiting ; Prospective Studies ; Quality of Life ; Spine ; Wounds and Injuries

Mesenchymal stem cells (MSCs) are useful candidates for tissue engineering and cell therapy. Physiological cell environment not only connects cells to each other, but also connects cells to the extracellular matrix that provide mechanical support, thus exposing the entire cell surface and activating signaling pathways. Hydrogel is a polymeric material that swells in water and maintains a distinct 3-dimensional (3D) network structure by cross linking. In this study, we investigated the optimized cellular function for canine adipose tissue-derived MSCs (cAD-MSCs) using hydrogel. We observed that the expression levels of Ki67 and proliferating cell nuclear antigen, which are involved in cell proliferation and stemness, were increased in transwell-hydrogel (3D-TN) compared to the transwell-normal (TN). Also, transforming growth factor-β1 and SOX9, which are typical bone morphogenesis-inducing factors, were increased in 3D-TN compared to the TN. Collagen type II alpha 1, which is a chondrocyte-specific marker, was increased in 3D-TN compared to the TN. Osteocalcin, which is a osteocyte-specific marker, was increased in 3DTN compared to the TN. Collectively, preconditioning cAD-MSCs via 3D culture systems can enhance inherent secretory properties that may improve the potency and efficacy of MSCs-based therapies for bone regeneration process.
Bone Regeneration ; Cell Proliferation ; Cell- and Tissue-Based Therapy ; Chondrogenesis ; Collagen Type II ; Extracellular Matrix ; Hydrogel ; Hydrogels ; Mesenchymal Stromal Cells ; Osteocalcin ; Osteogenesis ; Polymers ; Proliferating Cell Nuclear Antigen ; Tissue Engineering ; Water

Novel hydrogel composed of both chondroitin sulfate (CS) and gelatin was developed for better cellular interaction through two step double crosslinking of N-(3-diethylpropyl)-N-ethylcarbodiimide hydrochloride (EDC) chemistries and then click chemistry. EDC chemistry was proceeded during grafting of amino acid dihydrazide (ADH) to carboxylic groups in CS and gelatin network in separate reactions, thus obtaining CS–ADH and gelatin–ADH, respectively. CS–acrylate and gelatin–TCEP was obtained through a second EDC chemistry of the unreacted free amines of CS–ADH and gelatin–ADH with acrylic acid and tri(carboxyethyl)phosphine (TCEP), respectively. In situ CS–gelatin hydrogel was obtained via click chemistry by simple mixing of aqueous solutions of both CS–acrylate and gelatin–TCEP. ATR-FTIR spectroscopy showed formation of the new chemical bonds between CS and gelatin in CS–gelatin hydrogel network. SEM demonstrated microporous structure of the hydrogel. Within serial precursor concentrations of the CS–gelatin hydrogels studied, they showed trends of the reaction rates of gelation, where the higher concentration, the quicker the gelation occurred. In vitro studies, including assessment of cell viability (live and dead assay), cytotoxicity, biocompatibility via direct contacts of the hydrogels with cells, as well as measurement of inflammatory responses, showed their excellent biocompatibility. Eventually, the test results verified a promising potency for further application of CS–gelatin hydrogel in many biomedical fields, including drug delivery and tissue engineering by mimicking extracellular matrix components of tissues such as collagen and CS in cartilage.
Amines ; Cartilage ; Cell Survival ; Chemistry ; Chondroitin Sulfates ; Chondroitin ; Click Chemistry ; Collagen ; Extracellular Matrix ; Gelatin ; Hydrogel ; Hydrogels ; In Vitro Techniques ; Spectrum Analysis ; Tissue Engineering ; Transplants