A hyaluronic acid granular hydrogel nerve guidance conduit promotes regeneration and functional recovery of injured sciatic nerves in rats

A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regeneration.However,in vivo experiments have not been conducted.In this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve gap.The Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve transplantation.The conduit results were superior to those of a bulk hydrogel or silicone tube transplant.These findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic nerve.The nerve conduits have the potential as a material for repairing peripheral nerve defects.

Development of hyaluronic acid-based edible film for alleviating dry mouth

For alleviating dry mouth symptoms,edible films based on hyaluronic acid(HA)with 3 different m(800,1200 and 2300 kDa)were prepared(800 F,1200 F and 2300 F,respectively),and the properties as well as effectiveness were compared.The concentration of each HA dispersion for film forming was set as 3.0%,1.5%or 1.0%,for the m800,1200 and 2300 kDa,respectively,based on the solubility.The 800 F showed the highest thickness,tensile strength,and water vapor transparency,whereas obtained the lowest transparency and elongation at break among samples.All of the HA films showed safety against microorganism during 28 storage day at 40℃with 60%humidity.The optimum site for film attachment in mouth was the palate,and800 F was the most effective for stimulating saliva secretion,eliciting a 38%increase compared to control(without film),tested by the elderly over 65 years old.By the sensory test,800 F was also the most acceptable.Based on above results,the edible films effectively stimulating saliva secretion could be produced with HA,and the physical,sensory characteristics as well as disintegration times of the film could be controlled by mand the dissolution concentration of HA.

Hyaluronic acid injection in the auricular base for the aesthetic correction of lying ears:A retrospective study

Background Ears play an important role in facial profiles.Lying ears are not perceived favorably in Asian cultures;therefore,surgical procedures are implemented to adjust this defect.However,surgery has complications and requires recovery time.We introduced a hyaluronic acid(HA)injection technique to aesthetically improve ear prominence.Methods This retrospective study examined 25 Chinese patients aged 20-47 years with congenital lying ears who received HA injections in the auricular base at Shanghai Ninth People’s Hospital and Hangzhou Yijie Medical Cosmetology Clinic between November 2019 and December 2022.The average injection volume was 6.32​±​1.22 mL in the auricular base unilaterally,and the follow-up time ranged from 6 to 24 months.Morphological measurement data were recorded.Two-dimensional(2D)and three-dimensional(3D)images were obtained to evaluate the effects.Results All patients showed improvements in ear prominence.The cranioauricular angle(CAA)increased from 22.24°​±​4.53°to 65.90°​±​5.38°immediately post-injection and was maintained at 49.18°​±​4.74°6 months later.The ear projection(EP)increased from 14.75​±​2.72 mm to 26.26​±​2.94 mm immediately post-injection and was 22.51​±​2.68 mm after 6 months.No serious complications were noted.Conclusion HA injection in the auricular base effectively corrected the lying ears and aesthetically optimized the facial profile.It also had a face-lift effect that made the face look younger and more compact.The injection procedure was minimally invasive and required no recovery period.The effect was maintained for a long time and was satisfactory.

Design of Novel Wound Dressing Composed of Collagen and Hyaluronic Acid Containing Epidermal Growth Factor

This research aims to develop a wound dressing composed of collagen (Col) and hyaluronic acid (HA) containing epidermal growth factor (EGF). First important issue is to contain EGF in the wound dressing in a stable state. The sheet-shaped sponge was manufactured by freeze-vacuum drying an aqueous solution of Col. Both sides of sponge were treated with ultraviolet (UV) irradiation to introduce intermolecular cross links between collagen molecules. This sponge was named Sponge-Col. Another sheet-shaped sponge was manufactured by freeze-vacuum drying an aqueous solution of HA containing EGF. This sponge was named Sponge-HA/EGF. The wound dressing was manufactured by laminating Sponge-Col on the top, Sponge-HA/EGF in the middle, and Sponge-Col on the bottom to create a sandwich structure. This method can prevent the reducing of EGF activity due to UV irradiation for intermolecular cross-linking. Second important issue is to enable gradual release of EGF from the wound dressing. The elution behavior of this wound dressing was investigated by measuring the weight change after immersion in water for a predetermined time. This wound dressing showed initially fast elution and subsequent very slow elution properties. The upper layer and lower layer Sponge-Col enabled gradual release of the middle layer Sponge-HA/EGF. This result suggests that EGF contained in the wound dressing is gradually released together with HA from the wound dressing. Third important issue is to provide moist wound-healing environment. The upper layer and lower layer Sponge-Col can provide the wound dressing with high water absorption and long-term water retention properties.

A Guide to Cheek Augmentation: Single-Point Deep Injection of Hyaluronic Acid Filler at Midface in Close Proximity to Medial Suborbicularis Oculi Fat (SOOF) Area

Loss of volume in midface can result in an aged, wasted appearance. Osseous and fat atrophy with aging may further contribute to the loss of soft tissue support and midface ptosis. In the aging of periorbital area and midface, fat atrophy occurs mostly in the suborbicularis oculi fat (SOOF) area. The authors proposed that injection of hyaluronic acid (HA) filler to support the SOOF area could counteract the aging sign due to fat atrophy, restore volume loss and achieve a more youthful appearance. The authors described the treatment of 10 female patients who received CHAP®-particle hyaluronic acid (CHAP®-HA) injections for cheek augmentation, using single-point deep injection technique at midface in close proximity to SOOF area. Such approach provides satisfactory cheek augmentation results without significant complications. The authors discussed a rationale for their choice of dermal filler and provided an injection technique for restoring volume in the midface region with CHAP®-HA. Such technique is relatively quick to perform, have little down time, and result in a high rate of patient satisfaction.

Intraarticular injections(corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis

Osteoarthritis(OA)is a complex"whole joint"disease pursued by inflammatory mediators,rather than purely a process of"wear and tear".Besides cartilage degradation,synovitis,subchondral bone remodeling,degeneration of ligaments and menisci,and hypertrophy of the joint capsule take parts in the pathogenesis.Pain is the hallmark symptom of OA,but the extent to which structural pathology in OA contributes to the pain experience is still not well known.For the knee OA,intraarticular(IA)injection(corticosteroids,viscosupplements,blood-derived products)is preferred as the last nonoperative modality,if the other conservative treatment modalities are ineffective.IA corticosteroid injections provide short term reduction in OA pain and can be considered as an adjunct to core treatment for the relief of moderate to severe pain in people with OA.IA hyaluronic acid(HA)injections might have efficacy and might provide pain reduction in mild OA of knee up to 24 wk.But for HA injections,the costeffectiveness is an important concern that patients must be informed about the efficacy of these preparations.Although more high-quality evidence is needed,recent studies indicate that IA platelet rich plasma injections are promising for relieving pain,improving knee function and quality of life,especially in younger patients,and in mild OA cases.The current literature and our experience indicate that IA injections are safe and have positive effects for patient satisfaction.But,there is no data that any of the IA injections will cause osteophytes to regress or cartilage and meniscus to regenerate in patients with substantial and irreversible bone and cartilage damage.

Serum hyaluronic acid, procollagen type Ⅲ and Ⅳ in histological diagnosis of liver fibrosis

OBJECTIVE: To assess the significance of serum hyaluronic acid （HA）, proeollagen type Ⅲ （PCⅢ）,collagen type Ⅳ （CⅣ） in the histological diagnosis of liver fibrosis.METHODS: The concentrations of serum HA, PCⅢ, CⅣ in 253 patients with chronic liver diseases weremeasured by radioimmunoassay. Liver biopsies were performed in all patients at the same time. The liverwas pathologically evaluated by a pathologist according to a scoring system. Combined with the results ofliver pathological diagnosis, the accuracy of serum HA, PCⅢ, CⅣ in diagnosing patients with hepaticfibrosis （staging≥S2） or cirrhosis （S4） was assessed using the receiver operating curve （ROC）.RESULTS: The cutoff values of serum HA, PCⅢ and CⅣ for identifying patients with hepatic fibrosis（≥S2） or cirrhosis （S4） were determined. The cutoff values of serum HA, PCⅢ and CⅣ for detectingpatients with fibrosis （stage≥S2） were 90μg/L, 90μg/L, 75μg/L, respectively; their sensitivity（Se） was 80.4%, 82%, 63.1%; their specificity （Spe） was 70.2%, 60.8%, 83.8%; their positivepredictive values （PPV） were 86.7%, 83.5%, 90.4%; their negative predictive values （NPV） were59.8%, 58.4%, 48.4%, respectively. The cutoff values for detecting patients with liver cirrhosis were210μg/L for HA, 96.2% for Se, 85.3% for Spe, 65.4% for PPV, 98.8% for NPV; 150μg/L forPCⅢ, 76.4% for Se, 68.7% for Spe, 40.4% for PPV, 91.3% for NPV; 90μg/L for CⅣ, 80% forSe, 75.8% for Spe, 47.8% for PPV, 93.2% for NPV, respectively.CONCLUSIONS: Serum HA, PCⅢ and CⅣ can be determined for an accurate diagnosis of hepaticfibrosis in various stages. HA is the best for screening liver cirrhosis.

Influence of BOL on hyaluronic acid,laminin and hyperplasia in hepatofibrotic rats

AIM: To study the anti-hepatofibrosis mechanism of Bie Jie Jian oral liquid (BOL).METHODS: The model was induced by subcutaneous injection of CCl4. BOL was administered and the change of serum hyaluronic acid (HA) and laminin (LN) was observed and the degeneration of liver cells and the degree of fibre hyperplasia analyzed. Changes of ultra micro-structure in liver cells were observed in some samples.RESULTS: HA was reduced in both the groups with Iow and high dosage of BOL, which showed a remarkable difference as compared with that of the model group ( Iow dosage group: 376.15 μg/L ± 35.48 μg/L vs 806.07 μg/L ± 98.49 μg/L, P < 0.05; high dosage group: 340.14 μg/L ± 30.18 μg/L vs 806.07μg/L± 98.49 μg/L, P<0.05). The LN content of Iow and high dosage group of BOL was lower than that of model group (Iow dosage group: 71.99 μg/L± 8.15 μg/L vs 133.94μg/L± 14.45 μg/L, P< 0.01; high dosage group: 71.68 ig/L± 11.62 μg/L vs 133.94 μg/L ± 14.45 μg/L, P<0.01) and colchicine group (Iow dosage group: 71.99 μg/L ± 8.15 μg/Lvs 118.28 μg/L ± 16.13 μg/L, P< 0.05; high dosage group:71.68 μg/L ± 11.62 μg/L vs 118.28 μg/L ± 16.13 μg/L,P<0.05). Examined by Ridit, BOL could reduce the degeneration and necrosis of liver cells (X2 = 11.99P<0.05), the degree of fibre hyperplasia (X2 = 13.24P<0.05) and the pathological change of ultra micro-structure as well.CONCLUSION: The BOL has certain therapeutic effect on the experiment hepatofibrosis. Its mechanisms might include:protecting the function of liver cells, inhibiting excessive synthesis and secretion of extraceiluar matrix from hepatic stellate cells, relieving the cepillarization of hepatic sinueoid, improving liver micro-circulation, and regulating immune function.

Single-and double-dose of platelet-rich plasma versus hyaluronic acid for treatment of knee osteoarthritis: A randomized controlled trial

BACKGROUND Platelet-rich plasma(PRP)and hyaluronic acid have been shown to be useful in the treatment of knee osteoarthritis.However,investigations comparing the efficacy of these two drugs together are insufficient.AIM To compare the outcomes of PRP vs hyaluronic acid injections in three groups of patients with bilateral knee osteoarthritis.METHODS This randomized controlled trial study involved 95 patients.Thirty-one subjects received a single injection of PRP(group PRP-1),33 subjects received two injections of PRP at an interval of 3 wk(group PRP-2)and 31 subjects received three injections of hyaluronic acid at 1-wk intervals(group hyaluronic acid).The patients were investigated prospectively at the enrollment and at 4-,8-and 12-wk follow-up with the Western Ontario and McMaster Universities Arthritis Index(WOMAC)and Visual Analogue Scale questionnaires.RESULTS Percentages of patients experiencing at least a 30%decrease in the total score for the WOMAC pain subscale from baseline to wk 12 of the intervention were 86%,100%and 0%in the groups PRP-1,PRP-2 and hyaluronic acid,respectively(P<0.001).The mean total WOMAC scores for groups PRP-1,PRP-2 and hyaluronic acid at baseline were 63.71,61.57 and 63.11,respectively.The WOMAC scores were significantly improved at final follow-up to 42.5,35.32 and 57.26,respectively.The highest efficacy of PRP was observed in both groups at wk 4 with about 50%decrease in the symptoms compared with about 25%decrease for hyaluronic acid.Group PRP-2 had higher efficacy than group PRP-1.No major adverse effects were found during the study.CONCLUSION PRP is a safe and efficient therapeutic option for treatment of knee osteoarthritis.It was demonstrated to be significantly better than hyaluronic acid.We also found that the efficacy of PRP increases after multiple injections.

Preparation and characterization of nanoparticles from quaternized cyclodextrin-grafted chitosan associated with hyaluronic acid for cosmetics

Hyaluronic acid(HA, 20–50 kDa) is a hydrophilic macromolecule with anti-wrinkle effects and moisturizing properties. However, its high molecular weight prevents it from penetrating into the deeper layers of the skin and, thus, limits its benefits to topical effects. Thus, the objective of this study is to prepare nanoparticles of quaternized cyclodextrin-grafted chitosan(QCD-g-CS) associated with HA in different molar ratios of QCD-g-CS and HA. The conjugation of the carboxylic moieties of HA and the amides of QCD-g-CS was confirmed by Fourier-transform infrared spectroscopy. Thus, the system was optimized to create nanoparticles with a small size(235.63 ± 21.89 nm), narrow polydispersity index(0.13 ± 0.02), and zeta potential of 16.07 ± 0.65 m V. The association efficiency and loading efficiency were determined by ultra-performance liquid chromatography as 86.77 ± 0.69% and 10.85 ± 0.09%, respectively. The spherical morphology of the obtained nanoparticles was confirmed by transmission electron microscopy. Moreover, the in-vitro hydrating ability was significantly higher( P < 0.001) than that of bulk HA(3.29 ± 0.41 and 1.71 ± 0.05 g water/g sample, respectively). The safety of these nanoparticles at concentrations in the range of 0.01–0.10 mg/ml was confirmed via tests on human skin fibroblasts. Together, these results demonstrate that the developed nanoparticles are promising for future applications in cosmetics.

3D bioprinted hyaluronic acid‑based cell‑laden scaffold for brain microenvironment simulation

Treatments for lesions in central nervous system(CNS)are always faced with challenges due to the anatomical and physiological particularity of the CNS despite the fact that several achievements have been made in early diagnosis and precision medicine to improve the survival and quality of life of patients with brain tumors in recent years.Understanding the complexity as well as role of the microenvironment of brain tumors may suggest a better revealing of the molecular mechanism of brain tumors and new therapeutic directions,which requires an accurate recapitulation of the complex microenvironment of human brain in vitro.Here,a 3D bioprinted in vitro brain matrix-mimetic microenvironment model with hyaluronic acid(HA)and normal glial cells(HEBs)is developed which simulates both mechanical and biological properties of human brain microenvironment in vivo through the investigation of the formulation of bioinks and optimization of printing process and parameters to study the effects of different concentration of gelatin(GA)within the bioink and different printing structures of the scaffold on the performance of the brain matrix-mimetic microenvironment models.The study provides experimental models for the exploration of the multiple factors in the brain microenvironment and scaffolds for GBM invasion study.

Crosslinked hyaluronic acid with liposomes and crocin for management symptoms of dry eye disease caused by moderate meibomian gland dysfunction

AIM:To study the effect of uncrosslinked and crosslinked hyaluronic acid combined with other artificial tear components in patients with dry eye caused by moderate meibomian gland dysfunction.METHODS:Prospective,single-blind,contralateral eye study.Fifty eyes(25 patients)were analyzed.Eye selection for each tear type was random,and the eye drop formulations,0.4%uncrosslinked hyaluronic acid and 0.2%galactoxyloglucan(tear A)and 0.15%crosslinked hyaluronic acid,crocin,and liposomes(tear B)were used.The determined dosing schedule was three times a day for six weeks,and the study participants underwent a clinical examination before and 45 d after lubricant treatment.The Schirmer test,tear breakup time(TBUT)test,and Ocular Surface Disease Index(OSDI)questionnaire were applied before and after instillation period with both types of artificial tears.RESULTS:On the Schirmer test,a significant improvement was obtained with both tear A(P<0.01)and tear B(P<0.01).On the TBUT test,a significant improvement was obtained with tear A(P<0.01)and tear B(P<0.01).The OSDI score significantly decreased after instillation period with both artificial tear types(P<0.01).CONCLUSION:Uncrosslinked hyaluronic acid combined with other components,such as tamarind seed polysaccharide,and crosslinked hyaluronic acid combined with liposomes and crocin are effective for management symptoms of dry eye disease.

Role of artificial tears with and without hyaluronic acid in controlling ocular discomfort following PRK: a randomized clinical trial

AIM:To compare outcomes of applying preservative free artificial tears(PFAT)with and without hyaluronic acid(HA)in early postoperative course following photorefractive keratectomy(PRK).METHODS:In this triple-blinded randomized clinical trial,PRK procedure was performed on both eyes of 230 patients.Following PRK,patients were divided into three groups:the HA^(+)group,44 patients PFAT containing HA;the HA-group,71 patients PFAT without HA were administered 5 times per day(every 4 h);the third group,115 patients received no PFAT before lens removal.On the 1st and 4th postoperative day,Visual Analogue Score(VAS)was utilized to evaluate patient’s level of pain.Participants were asked to complete a questionnaire about the severity of eye discomfort ranked from 0 to 10(0=no complaint;10=most severe complaint experienced).RESULTS:In eyes receiving PFAT with or without HA(Drop group),mean scores for epiphora,foreign body sensation,and blurred vision on the 1st postoperative day were statistically lower(P<0.05).Filamentous keratitis(FK)was detected in 11(4.7%)eyes,and recurrent corneal erosion(RCE)was observed in 5(2.1%)eyes.In the control group,FK was noted in 16(6.9%)eyes while 13(5.6%)eyes had RCE and 5(2.1%)eyes had corneal haze.The rate of complications was statistically lower in Drop group(P=0.009).However,the aforementioned scores were not statically different between HA^(+)and HA-group one and two(P=0.29).CONCLUSION:Following PRK,applying PFAT with and without HA yields faster visual recovery,decreases postoperative ocular discomfor t and haze formation;however there is no additive effect for HA.

Adjunctive platelet-rich plasma and hyaluronic acid injection after arthroscopic debridement in Kellgren-Lawrence grade 3 and 4 knee osteoarthritis

BACKGROUND Osteoarthritis(OA)is the most common cause of pain and disability,predominantly affecting the knee.The current management of knee OA falls short of completely stopping disease progression,particularly in Kellgren-Lawrence(KL)grade 3 and 4 knee OA.As such,joint replacement is often recommended,although only 15%-33%of candidates accept it.Alternative therapeutic options are still needed to prevent the progression of joint damage and delay the need for knee arthroplasty.AIM To investigate the effect of adjunctive platelet rich plasma(PRP)and hyaluronic acid(HA)after arthroscopic debridement in KL grade 3 and 4 knee OA.METHODS This retrospective cohort study used the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)score and WOMAC sub-scores(pain,stiffness,and function)to assess 21 patients,grouped according to medical record data of treatment received:Arthroscopic debridement(n=7);arthroscopic debridement with PRP(n=7);or arthroscopic debridement with HA(n=7).WOMAC scores and sub-scores at baseline and at 3 mo and 5 mo posttreatment were recorded.The three-group data were statistically analyzed using the tests of paired t,one-way analysis of variance,and post hoc least significant difference.RESULTS All three treatment groups showed significant improvements in WOMAC score and sub-scores from before treatment to 3 mo and 5 mo after treatment.However,the arthroscopic debridement with PRP treatment group,in particular,showed a significantly lower WOMAC pain score than the group who received arthroscopic debridement alone at 5 mo after the procedure(P=0.03).CONCLUSION Compared to arthroscopic debridement alone,adjunctive PRP after arthroscopic debridement significantly lessened the patients’pain symptom.

Comparison of cytotoxicity and wound healing effect of carboxymethylcellulose and hyaluronic acid on human corneal epithelial cells

AIM: To investigate the cytotoxic effect on human corneal epithelial cells(HCECs) and the ability to faciliate corneal epithelial wound healing of carboxymethylcellulose(CMC) and hyaluronic acid(HA).METHODS: HCECs were exposed to 0.5% CMC(Refresh plus, Allergan, Irvine, California, USA) and 0.1% and 0.3%HA(Kynex , Alcon, Seoul, Korea, and Hyalein mini,Santen, Osaka, Japan) for the period of 30 min, and 4, 12,and 24 h. Methyl thiazolyl tetrazoiun(MTT)-based calorimetric assay was performed to assess the metabolic activity of cellular proliferation and lactate dehydrogenase(LDH) leakage assay to assess the cytotoxicity. apoptotic response was evaluated with flow cytometric analysis and fluorescence staining with Annexin V and propiodium iodide. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy. The wound widths were measured 24 h after confluent HCECs were scratch wounded.RESULTS: The inhibitory effect of human corneal epithelial proliferation and cytotoxicity showed the time-dependent response but no significant effect. Apoptosis developed in flow cytometry and apoptotic cells weredemonstrated in fluorescent micrograph. The damaged HCECs were detached from the bottom of the dish and showed the well-developed vacuole formations. Both CMC and HA stimulated reepithehlialization of HCECs scratched, which were more observed in CMC.CONCLUSION: CMC and HA, used in artificial tear formulation, could be utilized without any significant toxic effect on HCECs. Both significantly stimulated HCEC reepithelialization of corneal wounds.

Exploring the relationship of hyaluronic acid molecular weight and active targeting efficiency for designing hyaluronic acid-modified nanoparticles

Although it is reported that the targeting ability of hyaluronic acid(HA)-based nanoparticles(NPs) is molecular weight(MW) dependent,the influence of HA MW on targeting efficiency of HA-functionalized NPs and the underlying mechanism remain elusive. In this study,we constituted three HA-functionalized Dox-loaded NPs(Dox/HCVs) different HA MWs(7,63,and 102 k Da) and attempted to illustrate the effects of HA MW on the targeting efficiency.The three Dox/HCVs had similar physiochemical and pharmaceutical characteristics,but showed different affinity to CD44 receptor. Furthermore,Dox/HCV-63 exerted the best targeting effect and the highest cytotoxicity compared with Dox/HCV-7 and Dox/HCV-102. It was interesting to found that both the HA-CD44 binding affinity and induced CD44 clustering by HA-based NPs were HA MW-dependent,the two of which determine the apparent targeting efficacy of Dox/HCV NPs in the conflicting directions. Those results laid a good foundation for rationally designing HA-based NPs in cancer therapy.

Development of a Freeze-Dried Skin Care Product Composed of Hyaluronic Acid and Poly(γ-Glutamic Acid) Containing Bioactive Components for Application after Chemical Peels

Eight types of spongy sheet were prepared by freeze-drying aqueous solutions of hyaluronic acid (HA) and poly(γ-glutamic acid) (PGA) with or without bioactive components including vitamin C derivative (VC), glucosylceramide (GC), and epidermal growth factor (EGF). Spongy sheets were categorized into the following groups: Group I (HA/PGA), Group II (HA/PGA + VC), Group III (HA/PGA + GC), Group IV (HA/PGA + VC, GC), Group V (HA/PGA + EGF), Group VI (HA/PGA + VC, EGF), Group VII (HA/PGA + GC, EGF), and Group VIII (HA/PGA + VC, GC, EGF). In the first experiment, we examined fibroblast proliferation in conditioned medium that had been prepared by immersing each spongy sheet in a conventional culture medium. EGF-incorporating spongy sheets (Groups V-VIII) enhanced fibroblast proliferation more than EGF-free spongy sheets (Groups I-IV). In the second experiment, cytokine production by fibroblasts was evaluated using a wound surface model. This involved elevation of fibroblasts-incorporating collagen gel sheets to the air-liquid interface, on which a spongy sheet (Groups I, IV, V and VIII) was placed and cultured for 1 week. EGF-incorporating spongy sheets (Groups V and VIII) enhanced the production of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) by fibroblasts more than EGF-free spongy sheets (Groups I and IV). The effect of these four types of spongy sheet on wounds was investigated in animal experiments. Chemical peel was performed by contacting 50% trichloroacetic acid (TCA) on the dorsal region of mice, after which a spongy sheet was placed, and the wound condition was then observed in a two-week period. Angiogenesis was facilitated to a greater degree in Group VIII compared with Groups I, IV and V. This finding indicates that Group VIII spongy sheet is a promising aid for skin recovery after chemical peel.

Effect of the hyaluronic acid-poloxamer hydrogel on skin-wound healing: in vitro and in vivo studies

Background: Recent research into skin injury and wound healing has focused mainly on post‐trauma hemostasis, infection prevention, dermal regeneration and angiogenesis. However, less attention has been paid to air permeability and moisture loss prevention which also play important roles in injury healing. Methods: In the present work, we prepared a hyaluronic acid‐poloxamer (HA‐POL) hydrogel and tested the therapeutic effect of the hydrogel on skin‐wound healing. Results: The HA‐POL hydrogel transformed from sol to gel at 30°C, close to body temperature, and had stable moisturizing properties. HA‐POL hydrogel promoted skin‐wound healing and increased protein accumulation in the wound area. HA‐POL hydrogel allowed greater air permeability than Band‐aid, a typical wound covering. Results from transwell assays showed that the HA‐POL hydrogel effectively isolated skin‐wounds from bacterial invasion. Conclusion: This work demonstrates the advantages of using HA‐POL gel materials in the treatment of cutaneous wounds.

Effect on rabbits’intraocular structure by cross-linked hyaluronic formations as vitreous substitute

AIM:To develop a new material for retina filling and to investigate its effect on intraocular structure and histocompatibility in rabbit eyes.METHODS:The polymer-derived hyaluronic acid(HA)was formed by UV light cross-linked with N-vinyl-pyrrolidone.Vitrectomy was performed in the rabbits,and then crosslinked HA hydrogels at different concentrations were injected.Intraocular pressure measurements,cornea check-up,and B-ultrasound examination were performed during the follow-up period.After six weeks’follow-up,the rabbits were sacrificed,and both eyes were removed for hematoxylin-eosin(HE)staining,and the polymer materials were observed under electron microscopy.RESULTS:The particle size of the cross-linked HA hydrogels was mainly around at 100 nm.After vitrectomy and injection into vitreous cavity optical coherence tomography showed that the polymeric material HA had no significant effect on the overall thickness of the retina.The intraocular pressure returned to the normal level gradually at week 4.B-ultrasound results revealed that there is no significant change in the eye tissue given to HA material.The pathological and transmission electron microscopy results showed no obvious pathological change in the primary cells and rod cells under the retina tissue.CONCLUSION:HA-based cross-linked biopolymers has good biocompatibility in rabbit eyes,showing a promising potential as vitreous substitutes.

Hyaluronic acid inhibited the upregulation of heat-shock protein 70 in human chondrocytes from osteoarthritis and Kashin-Beck disease

This study aimed to investigate the effect of hyaluronic acid(HA)on the expression of heat-shock protein 70(HSP70)in chondrocytes isolated from patients with osteoarthritis(OA)and Kashin-Beck disease(KBD).The chondrocytes were collected from OA and KBD patients,and chondrocytes isolated from patients of accident injuries were used as the control.The chondrocytes were treated with HA at different doses.HSP70 expression in chondrocytes at both mRNA and protein levels was tested by PCR and Western blot analysis.Compared with control,both mRNA and protein levels of HSP70 were higher in chondrocytes from KBD and OA.However,HA at the dose of 500μg/mL significantly inhibited HSP70 expression levels in both KBD and OA groups(P<0.05).In conclusion,HSP70 is highly expressed in chondrocytes of patients of OA and KBD.HA intervention inhibits the upregulation of HSP70 in chondrocytes of OA and KBD patients and could be a promising agent for treatment of OA and KBD.