Different concentrations of hyaluronic acid eye drops for dry eye syndrome: a systematic review and Meta-analysis

AIM:To compare high or low concentration of hyaluronic acid eye drops(HY)for dry eye syndromes(DES).METHODS:Randomized controlled trials(RCTs)comparing various concentrations of HY were searched in PubMed,Embase,Web of Science,Cochrane,SinoMed,CNKI,Wanfang Database,CQVIP,and Chinese journals databases between inception and July 2023.Pooled standardized mean differences(SMD)or weighted mean difference(WMD)with 95%confidence intervals(CI)from RCTs evaluating Schirmer’s I test(SIT),corneal fluorescein staining score(CFS),tear breakup time(TBUT),DES score(DESS),and Ocular Surface Disease Index(OSDI)were calculated.Sensitivity analysis,Egger’s test and Meta-regression analysis were performed for all indicators.RESULTS:We conducted a Meta-analysis of 10 RCTs that met the inclusion criteria,involving 1796 cases.High-concentrations group significantly improved the outcome of CFS according to random effects modelling(SMD,-3.37;95%CI,-5.25 to-1.48;P=0.0005).The rest of the results were not statistically significant,including indicators such as SIT,TBUT,DESS and OSDI.CONCLUSION:For dry eyes with positive corneal staining,a high concentration of HY is recommended,whereas in other cases,a high concentration of HY does not offer a more pronounced advantage over a low concentration of HY in the treatment of dry eyes.

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.

Correlation Between Hyaluronic Acid,Hyaluronic Acid Synthase And Human Renal Clear Cell Carcinoma

Objective：To study the correlation between hyaluronic acid（HA）,hyaluronic acid synthase（HAS） and human renal clear cell carcinoma（RCCC）.Methods：The expression of three HAS isoforms＇ gene and HA in 93 RCCC tissues,27 nephridial tissues by the side of RCCC from two hospitals were measured with Real-Time RT-PCR、Western Blot and immunohistochemical methods and analyzed.Results：All RCCC and adjacent normal tissues expressed three HASs＇ mRNA protein;at the mRNA level,both RCCC and adjacent normal tissues,expressed more HAS3 than HAS1 or HAS2,their differences were statistically significant（all P values 0.05）;but,at the protein level,all HAS isoforms presented the equivalent expression.Compared with the adjacent non-neoplastic kidney tissues,the expression of all HAS isoforms＇ mRNA in RCCC tissues were increased evidently and their differences were significant（all P values 0.0001）;but at the protein level,only the expression of HAS3 increased evidently（P=0.022）.In all adjacent normal tissues,more than 80% renal tubular cells strongly expressed HA,however,only the minority RCCC cases（16/93） presented weakly positive HA staining in few cancer nests（5%-30%）,the difference were significant（P0.0001）.In RCCC tissues subgrouped according to clinical stage,pathological grade,lymphatic metastasis or not and distant metastasis or not,the HASs＇ mRNA protein differential expression all had no statistical significance（all P values 0.05）.Conclusion：Different from other malignancy,HA and HASs（except for HAS3） may not play important roles in the biological progress of human RCCC.

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.

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 were measured by radioimmunoassay. Liver biopsies were performed in all patients at the same time. The liver was pathologically evaluated by a pathologist according to a scoring system. Combined with the results of liver pathological diagnosis, the accuracy of serum HA, PCⅢ, CⅣ in diagnosing patients with hepatic fibrosis (staging≥S_2) or cirrhosis (S_4) was assessed using the receiver operating curve (ROC). RESULTS: The cutoff values of serum HA, PCⅢ and CⅣ for identifying patients with hepatic fibrosis (≥S_2) or cirrhosis (S_4) were determined. The cutoff values of serum HA, PCⅢ and CⅣ for detecting patients with fibrosis (stage≥S_2) 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 positive predictive values (PPV) were 86.7%, 83.5%, 90.4%; their negative predictive values (NPV) were 59.8%, 58.4%, 48.4%, respectively. The cutoff values for detecting patients with liver cirrhosis were 210μg/L for HA, 96.2% for Se, 85.3% for Spe, 65.4% for PPV, 98.8% for NPV; 150μg/L for PCⅢ, 76.4% for Se, 68.7% for Spe, 40.4% for PPV, 91.3% for NPV; 90μg/L for CⅣ, 80% for Se, 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 hepatic fibrosis in various stages. HA is the best for screening liver cirrhosis.

Preparation and Kinetics of a Novel Glutathione Peroxidase Mimic——Selenium-modified Hyaluronic Acid

A selenium-modified hyaluronic acid（HA） compound（SeHA） was synthesized as a mimic of glutathione peroxidase（GPX）. IR and NMR spectra of SeHA predict that the --CH2OH group of the N-acetyl-D-glucosamine in HA was modified by group --Sell. There are averagely 152 --Sell groups in one SeHA molecule. The GPX activities are 103.88, 32. 15 and 152. 71 U/μmol, respectively, when the substrates were H2O2, BuOOH and CuOOH. Ping-pong mechanism was observed in the steady-state kinetic studies of the reactive oxygen species（ROS） consuming reaction. Result of reactions of SeHA with free radical capturer 2,6-di-tert-butyl-4-methylphenol（BHT） shows that the catalysis is based on a non-free radical-mechanism and the SeHA can not be inhibited by iodoacetate, an enzyme inhibitor.

Preparation and Identification of Hyaluronic Acid From Fresh Pigskin

Hyaluronic acid （HA） had been prepared from pigskin residues with neutral proteinase. The preparing results and conditions were studied. After extracting and purification, HA was detected through ultraviolet spectra and infraction spectrum, and its content and purity were tested by carbazole and Elason-Morgan, respectively. This results indicated that significant quantities of HA could be prepared in fresh pigskin with biologic enzyme, and the pure HA was cosmetic grade and food grade.

No difference in high-magnification morphology and hyaluronic acid binding in the selection of euploid spermatozoa with intact DNA

In this study, we compared conventional sperm selection with high-magnification morphology based on the motile sperm organellar morphology examination （MSOME） criteria, and hyaluronic acid （HA） binding for sperm chromosome aneuploidy and DNA fragmentation rates. Semen from 50 severe male factor cases was processed through density gradient centrifugation, and subjected to sperm selection by using the conventional method （control）, high magnification at x6650 or HA binding. Aneuploidy was detected by fluorescence in situ hybridization with probes for chromosomes 13, 18, 21, X and Y, and DNA fragmentation by the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） method. Spermatozoa selected under high-magnification had a lower DNA fragmentation rate （2.6% vs. 1.7%; P=0.032）, with no significant difference in aneuploidy rate （0.8% vs0.7%; P=0.583）, than those selected by the HA binding method. Spermatozoa selected by both methods had much lower aneuploidy and DNA fragmentation rate than the controls （7% aneuploidy and 26.8% DNA fragmentation rates, respectively）. In the high-magnification group, the aneuploidy rate was lower when the best spermatozoa were selected than when only the second-best spermatozoa were available for selection, but the DNA fragmentation rate was not different. In conclusion, sperm selection under high magnification was more effective than under HA binding in selecting spermatozoa with low DNA fragmentation rate, but the small difference （0.9%） might not be clinically meaningful. Both methods were better than the conventional method of sperm selection.

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.

Purification and Structure Identification of Hyaluronic Acid

Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis,13C NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16×106D, which was measured by viscosity method.

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.

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.

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.

Optimization of Fermentation Process for Hyaluronic Acid Production by Streptococcus zooepidemicus

Hyaluronic acid （HA） is a high molecular weight glycosaminoglycan consisting of alternating D-glucuronic acid and N-acetylglueasamine and plays ex- tremely important roles in many biological processes. In this study, we optimized fermentation process for the production of HA by Streptococcus zooepidemicus ATCC35246, including fermentation broth composition and various fermentation parameters. The experimental results showed that the optimal fermentation broth composition was： glucose 45 g/L, yeast extract 10 g/L, tryptone 12 g/L, KH2PO4 2 g/L, K2HPO4 . 3H20 2 g/L, MgSO4 · 7H2O 2 g/L, and （NH4 ）2SO4 0.4 g/L. The optimal parameters involved in fermentation was： liquid volume 20%, pH 6. 0, rotation speed 180 r/min, fermentation temperature 35 ℃, fermentation duration 18 h, CTAB concentration 25 mg/L. Under the optimized conditions, the yield of HA was 0. 305 g/L, which was dramatically improved by 43.87% compared to that of 0. 212 g/L before optimization.

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.

Hyaluronic acid algorithm-based models for assessment of liver fibrosis： translation from basic science to clinical application

BACKGROUND： The estimation of liver fibrosis is usually dependent on liver biopsy evaluation. Because of its disadvantages and side effects, researchers try to find non-invasive methods for the assessment of liver injuries. Hyaluronic acid has been proposed as an index for scoring the severity of fibrosis, alone or in algorithm models. The algorithm model in which hyaluronic acid was used as a major constituent was more reliable and accurate in diagnosis than hyaluronic acid alone. This review described various hyaluronic acid algorithm-based models for assessing liver fibrosis.DATA SOURCE： A Pub Med database search was performed to identify the articles relevant to hyaluronic acid algorithmbased models for estimating liver fibrosis.RESULT： The use of hyaluronic acid in an algorithm model is an extra and valuable tool for assessing liver fibrosis.CONCLUSIONS： Although hyaluronic acid algorithm-based models have good diagnostic power in liver fibrosis assessment, they cannot render the need for liver biopsy obsolete and it is better to use them in parallel with liver biopsy. They can be used when frequent liver biopsy is not possible in situations such as highlighting the efficacy of treatment protocol for liver fibrosis.

Characteristics of Hyaluronic Acid Derivative Cross-linked by Polyethylene Glycol

Characteristic and dynamic viscosities of Hyaluronic acid （ HA ） derivative modified by polyethylene glycol （PEG） were tested with different reaction times （6 h,12 h,18 h and 24 h ）, different molar ratio of HA/PEG （1/10,1/5,1/3 and 1/2）, different molecular weight of PEG（400,6 000 and 20 000） and mass fraction is 0. 4% by Wushi Viscosimeter and L-90 Rheometer at 25℃ . Characteristic viscosity of HA derivative had the largest value in 12 h, which decreased with increasing of PEG molecular weight, bat its aqueous dynamic viscosity increased with increment of PEG molecular weight. Meanwhile, we tested dynamic mechanic properties of HA derivative by 3ARES3 Rheometer at 25℃ to study viscoelastic changes and to compare change difference from viscosity to elasticity with the changes of vibration frequency between unmodified HA and HA derivative. Change from low vibrated freqnency to high one of solution resulted in change from viscosity to elasticity of solution. In conclusion, as to the rheological properties, structure- modified HA derivative meets the requirement of biomaterial .