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: 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

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

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

OBJECTIVE: Ibuprofen, a nonsteroidal anti-inflammatory drug, is poorly soluble leading to its slow systemic absorption. This study aimed to optimize the formulation of an ibuprofen hydrogel-based matrix tablet to improve its dissolution for better oral bioavailability.

METHODS: Raw material of ibuprofen was subjected to quality control test and compatibility test with the excipients. Six trial formulations were performed, with polyethylene glycol (PEG) 6000 as the matrix for the first three trial formulations and carbopol for the remaining trial formulations. Finished product quality control (FPQC) tests were conducted to choose the best formulations to be compared against the marketed products using comparative dissolution and stability studies.

RESULTS: Among the trial formulations, Formulation 3 and Formulation 4 displayed highly satisfactory results from FPQC. The results of disintegration tests, comparative dissolution, and stability studies suggested carbopol as the better polymer over PEG 6000 which made Formulation 4 as the best.

CONCLUSION: Based on the percent drug release and similarity factor, it was concluded that the formulation optimized in this study was considered to be similar with the standard liquigel.

PURPOSE: The purpose of this paper was to determine the ability of a mixture consisting of mesenchymal stem cells, beta-tricalcium phosphate β-TCP), and hydrogel, to support cells and form new tissue. MATERIALS AND METHODS: A composite was produced by adding β-TCP to hydrogel, and mesenchymal stem cells were cultivated in the composite. Then, reverse transcription polymerase chain reaction (RT-PCR) was conducted to measure the level of gene expression for the new bone formation in the cells. Moreover, a composite in which the mesenchymal stem cells were added was injected into the subcutaneous fat of sprague-dawley rats. After four weeks, H&E, Masson trichrome, silver nitrate staining, and osterix immunohistochemical staining were conducted by taking the tissue to evaluate whether the composite supported mesenchymal stem cells and formed new tissue. RESULTS: By using RT-PCR, we found that the level of gene expression became significantly higher in 3-dimensional gel culture with RUNX2 by 1.26 times, with osteopontin by 1.23 times, transforming growth factor-β by 2.12 times, osterix by 1.07 times, type I collagen by 1.3 times, and fibronectin by 1.3 times. In the animal experiment in which a composite was transplanted into the subcutaneous fat, newly formed tissue was observed. Also, it was found that the composite prevented mesenchymal stem cells from leaving and formed new tissue. Osteogenic differentiation cells in the tissue was observed through osterix immunostaining. CONCLUSION: It was identified that the composite prevented mesenchymal stem cells dispersal and contributed to the formation of neogenic tissue. Therefore we conclude that the composite plays a role of a scaffold to support the implanted cells and form neogenic tissue more effectively.
Animal Experimentation ; Collagen Type I ; Fibronectins ; Gene Expression ; Hydrogel ; Mesenchymal Stromal Cells* ; Osteogenesis* ; Osteopontin ; Polymerase Chain Reaction ; Rats, Sprague-Dawley ; Reverse Transcription ; Silver Staining ; Subcutaneous Fat