Hyaluronidase: from clinical applications to molecular and cellular mechanisms

Resolve and dissolve-An ultrasound-guided investigation on the effects of hyaluronidase on different soft tissue fillers

BACKGROUND

Nonsurgical cosmetic procedures, particularly the use of hyaluronic acid (HA)-based soft tissue fillers, are becoming increasingly popular. This trend has catalyzed the development of a plethora of HA-based products differing in product characteristics, thereby catering to an ever-widening spectrum of aesthetic applications. However, complications rise concomitant with the increasing number of procedures. Among the strategies to manage such adverse events is the enzymatic breakdown with hyaluronidase.

OBJECTIVE

To analyze the response of different HA-based soft tissue filler materials to hyaluronidase injections.

METHODS

A total of 11 different HA-based soft tissue fillers were evaluated using noninvasive ultrasound imaging to assess their behavior in response to hyaluronidase injections. The HA-based soft tissue fillers were categorized according to their product characteristics into a structuring, volumizing, and lip volumizing group. Standardized injections of 0.2 cc were performed in chicken breast to simulate human tissue. Ultrasound measurements of width, height, and calculated volume were performed immediately after filler injection, 1 h and 24 h following hyaluronidase injection.

RESULTS

Regardless of the soft tissue filler analyzed, the most significant volume reduction occurred within the first h after applying hyaluronidase, with a 64.1% decrease from the initial volume. After 24 h, the total volume reduction reached 81.7%. No statistically significant differences were found when comparing the three groups at each follow-up time period, except for the height measurement after 1 h. While width was statistically significant in all groups between the investigated follow-up groups, the volume reduction was only statistically significant in the groups with the highest and second highest G' values (i.e., Group 1-structuring, Group 2-volumizing).

CONCLUSION

The effectiveness of hyaluronidase in dissolving HA-based fillers is initially independent of product characteristics of HA-based fillers such as G-prime, with increased efficacy in fillers with higher G-prime values, as evidenced by significant volume reductions in such groups.

Enhancing In Vivo Electroporation Efficiency through Hyaluronidase: Insights into Plasmid Distribution and Optimization Strategies

Electroporation (EP) stands out as a promising non-viral plasmid delivery strategy, although achieving optimal transfection efficiency in vivo remains a challenge. A noteworthy advancement in the field of in vivo EP is the application of hyaluronidase, an enzyme with the capacity to degrade hyaluronic acid in the extracellular matrix, which thereby enhances DNA transfer efficiency by 2- to 3-fold. This paper focuses on elucidating the mechanism of hyaluronidase's impact on transfection efficiency. We demonstrate that hyaluronidase promotes a more uniform distribution of plasmid DNA (pDNA) within skeletal muscle. Additionally, our study investigates the effect of the timing of hyaluronidase pretreatment on EP efficiency by including time intervals of 0, 5, and 30 min between hyaluronidase treatment and the application of pulses. Serum levels of the pDNA-encoded transgene reveal a minimal influence of the hyaluronidase pretreatment time on the final serum protein levels following delivery in both mice and rabbit models. Leveraging bioimpedance measurements, we capture morphological changes in muscle induced by hyaluronidase treatment, which result in a varied pDNA distribution. Subsequently, these findings are employed to optimize EP electrical parameters following hyaluronidase treatment in animal models. This paper offers novel insights into the potential of hyaluronidase in enhancing the effectiveness of in vivo EP, as well as guides optimized electroporation strategies following hyaluronidase use.

Efficacy and Safety of Fillers for the Treatment of Nasolabial Folds: A Network meta-Analysis of Randomized Controlled Trials

BACKGROUND

Nasolabial fold formation is increasingly becoming a cause of concern for many people. However, no network meta-analysis has compared the efficacy of different fillers in treating nasolabial folds. This network meta-analysis simultaneously compared the efficacy and safety of various fillers.

METHODS

We included randomized controlled trials (RCTs) that used fillers to treat nasolabial folds. We extracted data of Wrinkle Severity Rating Scale (WSRS), Global Esthetic Improvement Scale (GAIS, investigator) scores, GAIS scores (self-reported) and adverse events.

RESULTS

We included 13 RCTs. WSRS scores at 6 months were higher in patients receiving HA than those receiving poly (L-lactic acid) (mean difference [MD] 0.630, 95% confidence interval [CI] 0.275, 0.985) but significantly lower in patients receiving HA than in those receiving bovine collagen (MD - 0.580, 95% CI - 0.777, - 0.383) and porcine collagen (MD - 0.525, 95% CI - 0.790, - 0.260). Regarding adverse events, HA was significantly less likely to cause nodule formation compared with bovine collagen (RR 0.593, 95% CI 0.438, 0.803).

CONCLUSION

HA is a safe filler for correcting nasolabial folds, and poly (L-lactic acid) showed potential in treating nasolabial folds.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Structural identification and quantification of unreported sialylated N-glycans in bovine testicular hyaluronidase by LC-ESI-HCD-MS/MS

Bovine testicular hyaluronidase (BTH), which accelerates the absorption and dispersion of drugs by decomposing hyaluronan in subcutaneous tissues, has been used in medical applications, including local anesthesia, ophthalmology, and dermatosurgery. The requirement of N-glycans for the activity of human hyaluronidase has been reported, and BTH has greater activity than human hyaluronidase. However, the N-glycan characteristics of BTH are unclear. From a commercial BTH source containing additional proteins, purified BTH (pBTH) was obtained using size exclusion chromatography, and the structures and quantities of its N-glycans were analyzed using liquid chromatography (LC)-electrospray ionization-higher energy collisional dissociation (HCD)-tandem mass spectrometry (MS/MS). In pBTH, 32 N-glycans were identified, with 12 sialylations (39.0% of total N-glycan content), nine core-fucosylations (31.5%), six terminal galactosylations (14.6%), five high-mannosylations (13.7%), and four bisecting N-acetylglucosamine structures (7.8%). The presence of sialylated glycopeptides in pBTH was confirmed by nano-LC-HCD-MS/MS analysis. The absolute quantity of all N-glycans was calculated as 1.4 pmol (0.6 pmol for sialylation) in pBTH (1.0 pmol). The sialylation level (related to half-life, thermal stability, resistance to proteolysis, and solubility) was 24.4 times higher than that of human hyaluronidase. The hyaluronan degradation activity of de-sialylated pBTH decreased to 41.2 ± 4.2%, showing that sialylated N-glycans were required for pBTH activity as well. This is the first study to identify and quantify 32 N-glycans of pBTH and investigate their structural roles in its activity. The presence of larger amounts of sialylated N-glycans in pBTH than in human hyaluronidase suggests a greater utilization of pBTH.

Hyaluronidase impacts exposures of long-acting injectable paliperidone palmitate in rodent models

A significant challenge in the development of long-acting injectable drug formulations, especially for anti-infective agents, is delivering an efficacious dose within a tolerable injection volume. Co-administration of the extracellular matrix-degrading enzyme hyaluronidase can increase maximum tolerable injection volumes but is untested for this benefit with long-acting injectable formulations. One concern is that hyaluronidase could potentially alter the tissue response surrounding an injection depot, a response known to be important for drug release kinetics of long-acting injectable formulations. The objective of this pilot study was to evaluate the impact of co-administration of hyaluronidase on the drug release kinetics, pharmacokinetic profiles, and injection site histopathology of the long-acting injectable paliperidone palmitate for up to four weeks following intramuscular injection in mouse and rat models. In both species, co-administration of hyaluronidase increased paliperidone plasma exposures the first week after injection but did not negate the overall long-acting release nature of the formulation. Hyaluronidase-associated modification of the injection site depot was observed in mice but not in rats. These findings suggest that further investigation of hyaluronidase with long-acting injectable agents is warranted.

A Scoping Review of Hyaluronidase Use in Managing the Complications of Aesthetic Interventions

BACKGROUND

Hyaluronidase is used as an adjunct or main treatment to manage complications associated with cosmetic hyaluronic acid (HA) filler injections such as necrosis, blindness, hypersensitivity, delayed nodules, and poor aesthetic outcomes.

OBJECTIVE

To systematically map the available evidence and identify the gaps in knowledge on the effectiveness of hyaluronidase use in managing the aesthetic complications associated with HA injections (vascular occlusion, blindness, nodules, delayed hypersensivity, granuloma, poor aesthetic outcome).

METHODS

PubMed, Medline, Embase and Cochrane databases were used up to May 2022, to look for randomized clinical trials (RCTs), clinical trials, and retrospective case-control studies reporting on the use of hyaluronidase for managing the HA filler injection complications.

RESULTS

The database search yielded 395 studies; of those 5 RCTs (all carried out in the USA) were selected (53 subjects), indicating the effectiveness of hyaluronidase for removal of un-complicated injected HA nodules (forearm, upper arm, or back skin). The follow-ups ranged from 14 days to 4 years. The amount of HA filler injected into each site varied from 0.2 to 0.4 mL. A dose dependent response was observed for most HA fillers. No major adverse reactions were reported. Overall, for removal of every 0.1 mL of HA filler they injected 1.25-37.5 units of hyaluronidase (single injections). When 3 consecutive weekly hyaluronidase injection was used much lower doses of 0.375-2.25 unit was utilised. There was no evidence in a form of RCTs, clinical trials, and retrospective case-control studies on the removal/reversal of HA injections in the facial skin, or management of over-corrections, inflammatory nodules, or tissue ischemia/necrosis associated with HA filler injection.

CONCLUSION

Based on studies on the forearm, upper arm and back skin, hyaluronidase can be used for the reversal of uncomplicated HA filler injection nodule. However, further adequately powered studies are warranted to establish the ideal treatment protocol/dose of hyaluronidase for reversal of HA filler injections in the facial region or management of complications associated with aesthetic HA injection.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Enhancing hyaluronidase enzyme activity: Insights from advancement in bovine and ovine testicular hyaluronidase purification

This essay investigates the use of an affinity resin named Capto lentil lectin for the purification of bovine and ovine testicular hyaluronidase. Hyaluronidase, an enzyme that degrades hyaluronic acid, is used widely in medical fields like dermatology, orthopedics, and ophthalmology. The research highlights the importance of optimizing the purification process to increase enzyme activity and purity. A new purification method is proposed, which begins with ammonium sulfate precipitation, followed by Blue Sepharose and Capto Lentil Lectin chromatography. This novel approach significantly increases the yield, purity, and activity of the enzyme. This study paves the way for further research into improving the purification process. The study further discusses challenges in identifying hyaluronidase bands using SDS-PAGE and highlights the necessity of using Western blotting for precise results.

Hyaluronidase for Dermal Filler Complications: Review of Applications and Dosage Recommendations

BACKGROUND

Hyaluronidase (Hyal) can reverse complications of hyaluronic acid (HA) fillers, which has contributed substantially to the popularity of such procedures. Still, there are differing opinions regarding Hyal treatment, including dosage recommendations in filler complication management.

OBJECTIVE

We aimed to address unanswered questions regarding Hyal treatment for HA filler complications, including timing and dosage, skin pretesting, properties of various Hyals and interactions with HA gels, and pitfalls of the treatment.

METHODS

PubMed and Google Scholar databases were searched from inception for articles on Hyal therapy for filler complications. Articles were evaluated regarding their contribution to the field. The extensive literature review includes international leaders' suggestions and expert panels' recommendations.

RESULTS

There are limited controlled data but increasing clinical experience with Hyal treatment. The currently used Hyals provide good results and have an acceptable safety profile. Nonemergent complications such as the Tyndall effect, noninflamed nodules, and allergic or hypersensitivity reactions should be treated with low or moderate Hyal doses. Hyal should be considered with prior or simultaneous oral antibiotic treatment in managing inflammatory nodules. Hyal may be tried for granulomas that have not responded to intralesional steroids. Emergent complications such as vascular occlusion and blindness require immediate, high-dose Hyal treatment. Regarding blindness, the injection technique, retrobulbar versus supraorbital, remains controversial. Ultrasound guidance can increase the efficacy of the above interventions.

CONCLUSIONS

Hyal is essential in aesthetic practice because it can safely treat most HA filler complications. Immediate Hyal treatment is required for emergent complications. Aesthetic practitioners should be versed in using Hyal and effective dosage protocols.

The prevention and management of postoperative trachomatous trichiasis: A systematic review

Among ocular infections, trachoma is the main cause of blindness. Repeated conjunctival Chlamydia trachomatis infections lead to trichiasis, corneal opacification, and visual impairment. Surgery is often needed to relieve discomfort and preserve vision; however, a high postoperative trachomatous trichiasis (PTT) rate has been observed in various settings. We wanted to know why, whether PTT rates could be reduced, and how to manage the PTT that occurs. We performed a search of the literature. Of 217 papers screened, 59 studies were identified for inclusion as potentially relevant, the majority having been excluded for not directly concerning PTT in humans. Preventing PTT is a major challenge. Only one published trial, the STAR trial in Ethiopia, has reported a cumulative PTT rate <10% one year after surgery. The literature on the management of PTT is sparse. Though no PTT management guidelines are available, high-quality surgery with a low rate of unfavorable outcomes for PTT patients is likely to require enhanced training of a smaller group of highly-skilled surgeons. Based on the surgical complexity and the authors' own experience, the pathway for patients suffering from PTT should be studied further for improvement.

Surgical rhinoplasty after prior hyaluronic acid based nose remodeling

BACKGROUND

Medical rhinoplasty by hyaluronic acid injection (HA) has become nowadays a common practice. The number of patients requesting surgical rhinoplasty and having already undergone one or more injections of HA is increasing. However, the literature lacks publications regarding the management of these patients.

OBJECTIVES

The aim of this study is to discuss the management of patients who have been treated with previous nasal HA injections and who seek surgical rhinoplasty, and elaborate a treatment protocol and algorithm to standardize surgical plans.

METHODS

We are reporting case studies based on our clinical experience. We also reviewed the literature to suggest perioperative management for rhinoplasty with previous HA injections.

RESULTS

Hyaluronidase injection preoperatively allows to carry out an accurate preoperative analysis of the nasal deformities to treat, in order to make an adapted treatment plan. Postoperative course is similar to other rhinoplasty cases without the use of this enzyme.

CONCLUSION

Hyaluronidase should be used in all patients with nasal injections of HA (unless contraindications), who are willing to undergo a surgical rhinoplasty. The operation can be undertaken at one-week interval as soon as the edema subsides and no further treatments are necessary.

Identification, quantification, and structural role of N-glycans in two highly purified isoforms of sheep testicular hyaluronidase

Animal-derived hyaluronidase, which hydrolyzes the polysaccharide hyaluronic acid, has been used in medical applications despite its limited purity. Additionally, the N-glycan characterization of sheep testicular hyaluronidase (STH) and its structural role remain poorly understood. In this study, STH was purified from the commercially available STH preparation (containing at least 14 impurity proteins) using heparin-affinity chromatography followed by size exclusion chromatography. The structure and quantity of N-glycans of STH were investigated using liquid chromatography-electrospray ionization-high energy collision dissociation-tandem mass spectrometry. Two isoforms, H3S1 and H3S2, of STH were obtained (purity >98 %) with a yield of 3.4 % and 5.1 %, respectively. Fourteen N-glycans, including nine core-fucosylated N-glycans (important for the stability and function of glycoproteins), were identified in both H3S1 and H3S2, with similar quantities of each N-glycan. The amino acid sequences of the proteolytic peptides of H3S1 and H3S2 were compared with those reported in STH. The hyaluronic acid-degrading activity of deglycosylated H3S1 and H3S2 was reduced to 70.8 % and 71.1 % compared to that (100 %) of H3S1 and H3S2, respectively. This is the first report of N-glycan characterization of two highly purified isoforms of STH. These H3S1 and H3S2 will be useful for medical use without unwanted effects of partially purified STH.

Identifying a predictive relationship between maximal flow rate and viscosity for subcutaneous administration of macromolecules with recombinant human hyaluronidase PH20 in a miniature pig model

Subcutaneous (SC) infusion of large volumes at rapid flow rates has historically been limited by the glycosaminoglycan hyaluronan (HA), which forms a barrier to bulk fluid flow in the SC space. Recombinant human hyaluronidase PH20 (rHuPH20) depolymerizes HA, temporarily eliminating this barrier to rapid SC delivery of large volume co-administered therapeutics. Using a miniature pig model, in-line pressure and applied force to the delivery hardware were measured when subcutaneously infusing a representative macromolecule (human polyclonal immunoglobulin [Ig]), at varying concentrations and viscosities (20-200 mg/mL), co-formulated with and without rHuPH20 (2000 U/mL and 5000 U/mL). Maximal flow rate (Qmax) was calculated as the flow rate producing a statistically significant difference in mean applied force between injections administered with or without rHuPH20. There was a significant reduction in mean applied force required for SC delivery of 100 mg/mL Ig solution with 5000 U/mL rHuPH20 versus Ig solution alone. Similar significant reductions in mean applied force were observed for most Ig solution concentrations, ranging from 25-200 mg/mL when administered with or without 2000 U/mL rHuPH20. Qmax was inversely proportional to Ig solution viscosity and Qmax for solutions co-formulated with 5000 U/mL rHuPH20 was approximately double that of 2000 U/mL rHuPH20 solutions. Mathematical simulation of a hypothetical 800 mg Ig dose co-formulated with rHuPH20 showed that delivery times <30 s could be achieved across a broad range of concentrations. Addition of rHuPH20 can help overcome volume and time constraints associated with SC administration across a range of concentrations in a dose-dependent manner.

Dermato-cosmeceutical properties of Pseudobombax ellipticum (Kunth) Dugand: Chemical profiling, in vitro and in silico studies

Plant extracts and their individual components have been used to manage skin aging for several decades. Recently, the discovery of new natural bioactive agents, that not only enhance the skin health but also offer protection against various deleterious factors, such as free radicals, ultraviolet radiation, and microbial infections, has been a potential target by many researchers. The aim of the current work was to investigate the phytochemical profile of an ethanol bark extract from Pseudobombax ellipticum, and to evaluate its antioxidant, antiaging and antibacterial activities in vitro. Molecular docking and molecular dynamics studies were adopted to estimate and confirm the binding affinity of several compounds and explain their binding pattern at the binding sites of four target enzymes associated with skin aging, namely collagenase, elastase, tyrosinase, and hyaluronidase. HPLC-MS/MS analysis led to the tentative identification of 35 compounds comprising phenolic acids, and their glycosides, procyanidins and flavonoid glycosides. The extract demonstrated a promising in vitro antioxidant activity in the DPPH and FRAP assays (IC50 56.45 and 15.34 μg/mL, respectively), and was able to inhibit the aforementioned key enzymes with comparable results to the reference drugs. In addition, the extract (6.25 mg/mL) inhibited the biofilm production of Pseudomonas aeruginosa and diminished the swimming and swarming motilities. The docked compounds revealed appreciable binding energy with the tested enzymes and were stable throughout the molecular dynamic simulations. In view of this data, P. ellipticum bark can be regarded as a good candidate for prospective application in derma-cosmeceutical preparations.

Potential targeting of the tumor microenvironment to improve cancer virotherapy

In 2015, oncolytic virotherapy was approved for clinical use, and in 2017, recombinant adeno-associated virus (AAV) delivery was also approved. However, systemic administration remains challenging due to the limited number of viruses that successfully reach the target site. Although the US Food and Drug Administration (FDA) permits the use of higher doses of AAV to achieve greater rates of transduction, most AAV still accumulates in the liver, potentially leading to toxicity there and elsewhere. Targeting the tumor microenvironment is a promising strategy for cancer treatment due to the critical role of the tumor microenvironment in controlling tumor progression and influencing the response to therapies. Newly discovered evidence indicates that administration routes focusing on the tumor microenvironment can promote delivery specificity and transduction efficacy within the tumor. Here, we review approaches that involve modifying viral surface features, modulating the immune system, and targeting the physicochemical characteristics in tumor microenvironment to regulate therapeutic delivery. Targeting tumor acidosis presents advantages that can be leveraged to enhance virotherapy outcomes and to develop new therapeutic approaches that can be integrated with standard treatments.

Tuning the crosslinking and degradation of hyaluronic acid/gelatin hydrogels using hydrogen peroxide for muscle cell sheet fabrication

Cell sheets have immense potential for medical and pharmaceutical applications including tissue regeneration, drug testing, and disease modelling. In this study, composite hydrogels were prepared from a mixture of phenolated hyaluronic acid (HA-Ph) and gelatin (Gelatin-Ph), with a controlled degree of polymer crosslinking and degradation, to fabricate muscle cell sheets from myoblasts. These hydrogels were obtained via hydrogen peroxide (H2O2)-mediated crosslinking catalysed by horseradish peroxidase (HRP) and peroxide-mediated cleavage of the polymer chains. The degrees of crosslinking and degradation were modulated by altering the exposure time to air containing H2O2. The results showed that exposing a solution of 2% w/v HA-Ph, 0.75% w/v Gelatin-Ph, and 1 unit mL-1 HRP to air with 16 ppm H2O2 for 60 min yielded a stiffer hydrogel (7.16 kPa Young's modulus) than exposure times of 15 min (0.46 kPa) and 120 min (3.98 kPa). Moreover, mouse myoblast C2C12 cells cultured on a stiff hydrogel and induced to undergo myogenic differentiation formed longer and higher-density myotubes than those on softer hydrogels. The cell sheets were readily detached within 5 min by immersing the HA-Ph/Gelatin-Ph hydrogels covered with a monolayer of cells in a medium containing hyaluronidase. Our findings demonstrate that composite hydrogels with properties tuned by controlling the exposure time to H2O2, show great promise as platforms for muscle cell sheet fabrication.

Orbital Dynamics and Efficacy of Retrobulbar Anesthesia With and Without Hyaluronidase in Vitreoretinal Surgery

Purpose: To compare retrobulbar anesthesia injection (RAI) with hyaluronidase and without hyaluronidase in vitreoretinal surgery using clinical efficacy measures and orbital manometry (OM). Methods: This prospective randomized double-masked study enrolled patients who had surgery using an 8 mL RAI with or without hyaluronidase. Outcome measures were clinical block effectiveness (akinesia, pain scores, need for supplemental anesthetic or sedative medications) and orbital dynamics assessed by OM before and up to 5 minutes after RAI. Results: Twenty-two patients received RAI with hyaluronidase (Group H+), and 25 received RAI without hyaluronidase (Group H-). Baseline characteristics were well matched. No differences in clinical efficacy were found. OM showed no difference in preinjection orbital tension (4 ± 2 mm Hg in both groups) or calculated orbital compliance (0.6 ± 0.3 mL/mm Hg, Group H+; 0.5 ± 0.2 mL/mm Hg, Group H-) (P = .13). After RAI, the peak orbital tension was 23 ± 15 mm Hg in Group H+ and 24 ± 9 mm Hg in Group H- (P = .67); it declined more rapidly in Group H+. Orbital tension at 5 minutes was 6 ± 3 mm Hg in Group H+ and 11 ± 5 mm Hg in Group H- (P = .0008). Conclusions: OM showed faster resolution of post-RAI orbital tension elevation with hyaluronidase; however, there were no clinically evident differences between groups. Thus, 8 mL RAI with or without hyaluronidase is safe and can achieve excellent clinical results. Our data do not support the routine use of hyaluronidase with RAI.

Recent Advances in Pharmaceutical Approaches of Antimicrobial Agents for Selective Delivery in Various Administration Routes

Globally, the increase of pathogenic bacteria with antibiotic-resistant characteristics has become a critical challenge in medical treatment. The misuse of conventional antibiotics to treat an infectious disease often results in increased resistance and a scarcity of effective antimicrobials to be used in the future against the organisms. Here, we discuss the rise of antimicrobial resistance (AMR) and the need to combat it through the discovery of new synthetic or naturally occurring antibacterial compounds, as well as insights into the application of various drug delivery approaches delivered via various routes compared to conventional delivery systems. AMR-related infectious diseases are also discussed, as is the efficiency of various delivery systems. Future considerations in developing highly effective antimicrobial delivery devices to address antibiotic resistance are also presented here, especially on the smart delivery system of antibiotics.

Time- and Dose-Dependent Effects of Hyaluronidase on the Degradation of Different Hyaluronan-Based Fillers In Vitro

BACKGROUND

Hyaluronidase (HYAL) is regarded as the standard for the management of complications associated with hyaluronan (HA)-based fillers. Therefore, the understanding of interactions of HA fillers and HYAL is essential.

METHODS

Nine different commercially available HA fillers (Belotero, Juvéderm, and Restylane) with varying degrees of cross-linking were used for the analysis. Fluorescently dyed HA fillers were individually incubated with varying doses of HYAL [bovine HYAL (Hylase "Dessau"; Riemser Pharma, Germany); 5, 10, and 20 U/mL] or sodium chloride and monitored by time-lapse microscopy. HA filler degradation was assessed as a decrease in fluorescence intensity of HA filler plus HYAL compared to HA filler plus control, quantified by computerized image analysis.

RESULTS

HA fillers show significant differences in their reaction to HYAL. Levels of degradation of HA fillers are positively correlated with increasing concentrations of HYAL. At the highest concentration of HYAL (20 U/mL), all fillers except one (Belotero Volume) reached a significant level of degradation at 5 to 9 hours.

CONCLUSIONS

In this study, the authors show that most HA fillers can be dissolved by HYAL in a dose- and time-dependent manner. Of note, the fillers' technology and degree of cross-linking seem to exert stronger effects on the degradability by HYAL as compared to the concentration of HA.

CLINICAL RELEVANCE STATEMENT

The authors' in vitro analyses support clinical recommendations stating that in the case of a vascular filler incident, HYAL should be applied early and at significant doses ("Time is skin!").

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Fast and efficient identification of hyaluronidase specific inhibitors from Chrysanthemum morifolium Ramat. using UF-LC-MS technique and their anti-inflammation effect in macrophages

The purpose of the study was to establish a rapid analytical strategy to screen potential anti-inflammatory compounds from Flos Chrysanthemum flower. The enzyme assay was conducted to prescreen botanical extracts, in which Chrysanthemum morifolium aqueous extract (CME) displayed hyaluronidase (HAase) inhibitory activity in a dose-dependent manner with the values of 8.31, 24.25, and 66.51% at concentrations of 1.00, 2.00, and 4 0.00 mg/mL, respectively. Eight potential compounds targeting HAase (compounds 9, 10, 11, 13, 15, 17, 20 and 21) from CME were screened using ultrafiltration affinity liquid chromatography coupled with mass spectrometry (UF-LC-MS) technology. The well-known inhibitor, dipotassium glycyrrhizinate (DG), was used as a positive control and competitive ligand to eliminate false positives. Then, four of these potential components (compounds 9, 10, 17, and 21), namely eriodictyol-7-O-glucoside, luteoloside, apigenin-7-O-glucoside and diosmetin-7-O-glucoside, were distinguished as potent HAase specific inhibitor candidates with high BD and CBD values. The enzyme inhibitory activities of candidate compounds were verified using enzyme inhibition assay. At a concentration of 1000 μM, compounds 9, 10, 17, and 21 showed 40.15, 44.85, 18.04, and 24.15% inhibition of HAase, respectively. Furthermore, all the four compounds significantly decreased the production of nitric oxide (NO) and IL-6, and significantly suppressed the mRNA expression of inducible NO synthase (iNOS) and IL-1β in both murine and human macrophages.

Structural Analysis and Classification of Low-Molecular-Weight Hyaluronic Acid by Near-Infrared Spectroscopy: A Comparison between Traditional Machine Learning and Deep Learning

Confusing low-molecular-weight hyaluronic acid (LMWHA) from acid degradation and enzymatic hydrolysis (named LMWHA-A and LMWHA-E, respectively) will lead to health hazards and commercial risks. The purpose of this work is to analyze the structural differences between LMWHA-A and LMWHA-E, and then achieve a fast and accurate classification based on near-infrared (NIR) spectroscopy and machine learning. First, we combined nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, two-dimensional correlated NIR spectroscopy (2DCOS), and aquaphotomics to analyze the structural differences between LMWHA-A and LMWHA-E. Second, we compared the dimensionality reduction methods including principal component analysis (PCA), kernel PCA (KPCA), and t-distributed stochastic neighbor embedding (t-SNE). Finally, the differences in classification effect of traditional machine learning methods including partial least squares-discriminant analysis (PLS-DA), support vector classification (SVC), and random forest (RF) as well as deep learning methods including one-dimensional convolutional neural network (1D-CNN) and long short-term memory (LSTM) were compared. The results showed that genetic algorithm (GA)-SVC and RF were the best performers in traditional machine learning, but their highest accuracy in the test dataset was 90%, while the accuracy of 1D-CNN and LSTM models in the training dataset and test dataset classification was 100%. The results of this study show that compared with traditional machine learning, the deep learning models were better for the classification of LMWHA-A and LMWHA-E. Our research provides a new methodological reference for the rapid and accurate classification of biological macromolecules.

The effects of female sexual hormones on the endothelial glycocalyx

The glycocalyx is a layer composed of carbohydrate side chains bound to core proteins that lines the vascular endothelium. The integrity of the glycocalyx is essential for endothelial cells' performance and vascular homeostasis. The neuroendocrine and immune systems influence the composition, maintenance, activity and degradation of the endothelial glycocalyx. The female organism has unique characteristics, and estrogen and progesterone, the main female hormones are essential to the development and physiology of the reproductive system and to the ability to develop a fetus. Female sex hormones also exert a wide variety of effects on other organs, including the vascular endothelium. They upregulate nitric oxide synthase expression and activity, decrease oxidative stress, increase vasodilation, and protect from vascular injury. This review will discuss how female hormones and pregnancy, which prompts to high levels of estrogen and progesterone, modulate the endothelial glycocalyx. Diseases prevalent in women that alter the glycocalyx, and therapeutic forms to prevent glycocalyx degradation and potential treatments that can reconstitute its structure and function will also be discussed.

The Role of Selected Flavonoids from Bajakah Tampala (Spatholobus littoralis Hassk.) Stem on Cosmetic Properties: A Review

Cosmetics made from natural ingredients are increasingly popular because they contain bioactive compounds which can provide many health benefits, more environmentally friendly and sustainable. The health benefits obtained from natural-based ingredients include anti-aging, photoprotective, antioxidant, and anti-inflammatory. This article reviewed the potential of selected flavonoids from bajakah tampala (Spatholobus littoralis Hassk.) as the native plant in Indonesia. We present in silico, in vitro, in vivo, and clinical research data on the use of selected flavonoids that have been reported in other extracts.

Efficacy of submucosal injection of hyaluronidase after mandibular third molar surgery: a randomized controlled trial

Objectives

This study aimed to investigate the efficacy of postoperative submucosal injection of hyaluronidase (HUD) for reducing sequelae and quality of life (QOL) after mandibular third molar (M3M) surgery.

Materials and Methods

Participants with bilateral impacted M3M underwent surgical extraction with a split-mouth randomized controlled study design. M3M were removed by the same surgeon in 2 sessions, one a control and the other experimental. Submucosal injection of HUD was performed in the experimental session and submucosal injection of saline in the control session. Mouth opening, facial swelling, and pain intensity were measured before surgery, and then 2 and 7 days after surgery. The QOL of participants following surgery was evaluated by means of a patient-centered outcome questionnaire (PCOQ).

Results

A total of 36 patients was included in the final data analysis. There was a significant reduction in the maximal mouth opening and postoperative pain in the experimental side at the 2 and 7 days after surgery (P<0.05), and a remarkable difference in facial swelling was reported on the experimental side 7 days after surgery (P<0.05). The PCOQ demonstrated that participants reported less pain and swelling on the experimental side.

Conclusion

The present study provides clinical evidence that submucosal administration of HUD immediately after M3M surgery reduced postoperative discomfort and improved patients' QOL.

Molecular mechanisms underlying hematophagia revealed by comparative analyses of leech genomes

BACKGROUND

Leeches have been used in traditional Chinese medicine since prehistoric times to treat a spectrum of ailments, but very little is known about their physiological, genetic, and evolutionary characteristics.

FINDINGS

We sequenced and assembled chromosome-level genomes of 3 leech species (bloodsucking Hirudo nipponia and Hirudinaria manillensis and nonbloodsucking Whitmania pigra). The dynamic population histories and genome-wide expression patterns of the 2 bloodsucking leech species were found to be similar. A combined analysis of the genomic and transcriptional data revealed that the bloodsucking leeches have a presumably enhanced auditory sense for prey location in relatively deep fresh water. The copy number of genes related to anticoagulation, analgesia, and anti-inflammation increased in the bloodsucking leeches, and their gene expressions responded dynamically to the bloodsucking process. Furthermore, the expanded FBN1 gene family may help in rapid body swelling of leeches after bloodsucking, and the expanded GLB3 gene family may be associated with long-term storage of prey blood in a leech's body.

CONCLUSIONS

The high-quality reference genomes and comprehensive datasets obtained in this study may facilitate innovations in the artificial culture and strain optimization of leeches.

Elucidations on the Performance and Reversibility of Treatment with Hyaluronic Acid Based Dermal Fillers: In vivo and in vitro Approaches

PURPOSE

The aim of this study was to investigate the performance and the reversibility of different classes of Hyaluronic Acid (HA) dermal fillers. We analysed 4 HA based fillers, belonging to 3 different chemical classes of products, commonly used in the field of wrinkles correction: linear HA 8 mg/mL (Viscoderm 0.8), thermically stabilized hybrid complexes of high and low molecular weight HA molecules at a concentration of 32 mg/mL and 45 mg/mL respectively (Profhilo and Profhilo Structura) and cross-linked HA 25 mg/mL (Aliaxin GP).

METHODS

The products were tested by a well-established animal model. The generated implants were analyzed through High-Frequency Ultrasound technology. Then, reversibility of the treatment was evaluated by enzymatic degradation kinetics studies, characterised by a combined approach of Carbazole assay and HP-SEC/TDA method.

RESULTS

Implants generated by linear HA 8 mg/mL remained detectable by ultrasound acquisition for 4 weeks, whereas those generated by injection of HA hybrid complex 32 mg/mL were detectable for 10 weeks. HA hybrid complex 45 mg/mL and cross-linked HA 25 mg/mL were detectable for 29 and at least 33 weeks, respectively. Enzymatic degradation kinetics studies demonstrated that the HA content in HA hybrid complex 45 mg/mL was almost completely depolymerized and homogeneous after 3 h of treatment. For cross-linked HA 25 mg/mL, 24 h of incubation are needed to obtain the same degree of depolymerization.

CONCLUSION

The study confirmed the ability of the experimental model to predict the behaviour of HA based dermal fillers in vivo and showed the innovative aspects of HA hybrid complex 45 mg/mL, that combines the high-safety profile, in terms of reversibility of the treatment, of the linear HA-based products with the durability of a high degree cross-linked gels, paving the way to the chance to be used for a wide range of applications in the field of aesthetic medicine.

Enzymatic Production of Low-Molecular-Weight Hyaluronan and Its Oligosaccharides: A Review and Prospects

Hyaluronic acid (HA) is a nonsulfated linear glycosaminoglycan with a negative charge. Different from the high-molecular-weight HAs, the low-molecular-weight HAs (LMW-HAs, 4-120 kDa) and hyaluronan oligosaccharides (O-HAs, <4 kDa) exhibit certain unique biological properties, owing to which these have a wide range of applications in the field of medicine. However, the chemical synthesis of high-purity LMW-HAs and O-HAs requires complex procedures, which renders this process difficult to achieve. The degradation of HA is achieved under the catalysis of hyaluronidases. In recent years, various hyaluronidase genes have been identified, and their enzymatic properties have been analyzed. In this context, the present review summarizes the hyaluronidases from different sources, which have been characterized. The review focuses on the crystal structure and the catalytic mechanism underlying the biological properties of hyaluronidases. In addition, the molecular weight distributions and the preparation approaches of the enzymatic products LMW-HAs and O-HAs are described. The general orientation of the research on hyaluronidases was speculated based on the existing literature. Accordingly, the efficient large-scale production of LMW-HAs and O-HAs using the green enzymatic approach was anticipated.

Hyaluronidase following buccal infiltrations of articaine with epinephrine for anesthesia of mandibular first molars: A split-mouth, double-blind, placebo-controlled randomized clinical trial

BACKGROUND

Adjunctive hyaluronidase has been widely used for ophthalmic anesthesia; however, in Dentistry, very few studies are available so far. Thus, the present study aimed to evaluate anesthetic outcomes of adjunctive hyaluronidase administration following buccal infiltration of articaine with epinephrine for anesthesia of mandibular first molars.

MATERIAL AND METHODS

Twenty-eight patients received a buccal supraperiosteal infiltration of 4% articaine with 1:100,000 epinephrine for anesthesia of the mandibular first molars, in a split-mouth approach. Afterward, randomly and using the same technique, they received either 1.0 mL of hyaluronidase (150 UTR/mL) or a placebo solution. Considering patients' pain perceptions provoked by electric and mechanical stimulations, as well as using a pain scale, success rate, action onset time, duration of both pulpal and soft tissue anesthesia, and pain immediately after both punctures and on the 2nd day were assessed.

RESULTS

The pulpal anesthetic success rate was 85.7% for hyaluronidase and placebo groups. Soft tissue anesthesia showed a shorter action onset time and a longer duration when hyaluronidase was used; however, there was no difference between the groups regarding action onset time and duration of pulpal anesthesia. Pain at the puncture sites did not differ between the groups, regardless of the time point evaluated.

CONCLUSIONS

Adjunctive hyaluronidase following buccal infiltration of articaine with epinephrine for mandibular first molars seems not to provide any advantage in anesthetic outcomes in which the nerve fibers are intraosseous (i.e., pulpal anesthesia). On the other hand, soft tissue anesthesia may be improved substantially by using this pharmacological strategy. Key words:Hyaluronidase, local anesthesia, dentistry.

Local anaesthetics in dermatological surgery: a review of adjuncts and pain reduction techniques

A variety of adjuncts for local anaesthesia (LA) exists for dermatological surgery, along with many options to reduce the pain of LA. This review aims to summarize the evidence relating to such adjuncts and methods to reduce the pain of LA. Adjuncts to LA can be an important consideration to optimize anaesthetic effect. Current evidence suggests that buffering and warming of LA fluid, along with cooling, pinching and administering vibrations to the skin are effective at reducing pain during administration. In this review, no significant difference in pain reduction was found between cooling and administering vibrations to the skin. Studies demonstrate that, overall, LA injection into distal sites is safe. However, the evidence specific to dermatological surgery is limited with regard to ways to reduce pain during LA injection and in determining the safety of LA for distal sites with confidence. Further high-quality research in the form of multicentre randomized controlled trials is required.

Adsorption of Methylene Blue on the Surface of Polymer Membrane; Dependence on the Isotopic Composition of Liquid Matrix

As was found in our previous works, when Nafion swells in water, polymer fibers unwind into the bulk of the surrounding liquid. This effect is controlled by the content of deuterium in water. Here, we present the results of studying the dynamics of methylene blue (MB) adsorption on the Nafion surface for MB solutions based on natural water (deuterium content is 157 ppm, the unwinding effect occurs) and based on deuterium-depleted water (DDW; deuterium content is 3 ppm, there is no unwinding). In addition, we studied the dynamics of water desorption during drying of the Nafion polymer membrane after soaking in MB solution based on natural water and DDW. It turned out that in the case of natural water, the rate of MB adsorption and water desorption is higher than in the case of DDW. It also turned out that the amount of MB adsorbed on the membrane in the case of natural water is greater than in the case of DDW. Finally, it was found that the desorption of water during drying is accompanied by a rearrangement of the absorption spectrum of Nafion. This rearrangement occurs earlier in the case of DDW. Thus, by infinitesimal changes in the deuterium content (from 3 to 157 ppm) in an aqueous solution, in which a polymer membrane swells, we can control the dynamics of adsorption and desorption processes. A qualitative model, which connects the observed effects with the slowing down of diffusion processes inside the layer of unwound fibers, is proposed.

Manufacturability of a Tetraethyl Orthosilicate-Based Hydrogel for Use as a Single Application Otitis Externa Therapeutic

Otitis externa, also known as outer ear infection, is a frequent affliction in both humans and animals. The most prevalent treatment for otitis externa is ear drops, but it is difficult to adhere properly to this treatment, causing poor patient compliance and the potential for complications. As a result, we have developed a tetraethyl orthosilicate-based hydrogel for use as single application treatment for otitis externa to increase ease of use and improve patient outcomes. Herein, we investigated the manufacturability of the hydrogel, focusing on several key aspects: formulation repeatability and reproducibility, material source and tolerances, release of a variety of model drugs, and impact of application-specific physiological factors, specifically local pH and enzymatic activity on drug release. Overall, our results indicate that these hydrogels are well suited for production and scalability, as they have a robust manufacturing process, have a wide tolerance for pH level, release a variety of model drugs, and are not impacted by outer ear canal-specific physiological factors.

Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)—Implications for Therapeutic Interventions

Biocompatible hyaluronic acid (HA, hyaluronan) gel implants have altered the therapeutic landscape of surgery and medicine, fostering an array of innovative products that include viscosurgical aids, synovial supplements, and drug-eluting nanomaterials. However, it is perhaps the explosive growth in the cosmetic applications of injectable dermal fillers that has captured the brightest spotlight, emerging as the dominant modality in plastic surgery and aesthetic medicine. The popularity surge with which injectable HA fillers have risen to in vogue status has also brought a concomitant increase in the incidence of once-rare iatrogenic vaso-occlusive injuries ranging from disfiguring facial skin necrosis to disabling neuro-ophthalmological sequelae. As our understanding of the pathophysiology of these injuries has evolved, supplemented by more than a century of astute observations, the formulation of novel therapeutic and preventative strategies has permitted the amelioration of this burdensome complication. In this special issue article, we review the relevant mechanisms underlying HA filler-induced vascular occlusion (FIVO), with particular emphasis on the rheo-mechanical aspects of vascular blockade; the thromboembolic potential of HA mixtures; and the tissue-specific ischemic susceptibility of microvascular networks, which leads to underperfusion, hypoxia, and ultimate injury. In addition, recent therapeutic advances and novel considerations on the prevention and management of muco-cutaneous and neuro-ophthalmological complications are examined.

An Italian Online Survey Regarding the Use of Hyaluronidase in Previously Hyaluronic Acid-Injected Noses Looking for Surgical Rhinoplasty

Background

Nonsurgical nasal reshaping (nSNR) with hyaluronic acid (HA) filler is a well-established procedure performed to ameliorate nasal appearance and is considered a valid alternative to surgical rhinoplasty in selected patients.

Objectives

The aim of our study is to evaluate the decision-making process and management of patients undergoing rhinoplasty, with previous HA filler injection, and evaluate if consensus could be achieved to recommend guidelines.

Methods

Between April and May 2021, an online survey was sent to 402 Italian surgeons of different specialties. The survey collected information regarding the types of treatment of patients who have previously undergone nSNR, who should undergo surgical rhinoplasty. For those surgeons using hyaluronidase, an additional information was collected.

Results

In a range of time of 2 months (April and May 2021), a total of 72 surgeons replied and completed the survey: out of the 402 questionnaires sent, the response rate was approximately 18%. The majority of respondents (61.5%) replied to inject hyaluronidase (HYAL) in patients who had to undergo a rhinoplasty but reported previous nSNR. Of the surgeons who use HYAL, 70% performed rhinoplasty after a waiting time of 3 to 4 weeks.

Conclusions

Either direct surgical approach or hyaluronidase injection first seems to be a viable options. The use of HYAL before surgery is the choice with the broadest consensus in our survey. However, a larger case-control study with long follow-ups is necessary to understand if in patient seeking surgical rhinoplasty who already received nSNR, the injection of hyaluronidase before surgery is mandatory, recommended, or not.

Paving the way towards effective plant-based inhibitors of hyaluronidase and tyrosinase: a critical review on a structure-activity relationship

Human has used plants to treat many civilisation diseases for thousands of years. Examples include reserpine (hypertension therapy), digoxin (myocardial diseases), vinblastine and vincristine (cancers), and opioids (palliative treatment). Plants are a rich source of natural metabolites with multiple biological activities, and the use of modern approaches and tools allowed finally for more effective bioprospecting. The new phytochemicals are hyaluronidase (Hyal) inhibitors, which could serve as anti-cancer drugs, male contraceptives, and an antidote against venoms. In turn, tyrosinase inhibitors can be used in cosmetics/pharmaceuticals as whitening agents and to treat skin pigmentation disorders. However, the activity of these inhibitors is stricte dependent on their structure and the presence of the chemical groups, e.g. carbonyl or hydroxyl. This review aims to provide comprehensive and in-depth evidence related to the anti-tyrosinase and anti-Hyal activity of phytochemicals as well as confirming their efficiency and future perspectives.

Does hyaluronidase injected in periocular area change skin ultrastructure: standardized in vitro analysis

BACKGROUND

Treatment with hyaluronic acid (HA) fillers as a strategy for rejuvenation has experienced a significant growth in recent years, accompanied by a parallel increase in its complications, the treatment of which, such as hyaluronidase, we must be aware of.

PATIENTS/METHODS

14 patients (28 eyes) had indication for upper blepharoplasty surgery in the Hospital Universitario y Politécnico La Fe. After surgery, periocular skin of one eye of each patient was infiltrated with 300 U of hyaluronidase (14 cases) while the skin of the fellow eye was preserved untreated (14 controls). All samples were studied by the Pathology department and finally 6 variables (skin structure alteration, degeneration of elastic fibers, deposits, collagen fibers destructuring, inflammation, other findings) were analyzed.

RESULTS

No differences in skin structure, elastic fibers and collagen dermal fibers were found between hyaluronidase treated skin and controls. A significant association between ex vivo application of hyaluronidase in periocular skin and the presence of amorphous extracellular deposits within the dermis was found.

CONCLUSIONS

Hyaluronidase applied ex vivo to periocular skin led to presence of deposits within the extracellular matrix compared to control eyelid skin but elastin and collagen dermis structure remained unaltered.

Semenogelin, a coagulum macromolecule monitoring factor involved in the first step of fertilization: A prospective review

Human male infertility affects approximately 1/10 couples worldwide, and its prevalence is found more in developed countries. Along with sperm cells, the secretions of the prostate, seminal vesicle and epididymis plays a major role in proper fertilization. Many studies have proven the functions of seminal vesicle secretions, especially semenogelin protein, as an optimiser for fertilization. Semenogelin provides the structural components for coagulum formation after ejaculation. It binds with eppin and is found to have major functions like motility of sperm, transporting the sperm safely in the immune rich female reproductive tract until the sperm cells reach the egg intact. The capacitation process is essential for proper fertilization and semenogelin involved in mediating capacitation in time. Also, it has control of events towards the first step in the fertilization process. It is a Zn ions binding protein, and Zn ions act as a cofactor that helps in the proper motility of sperm cells. Therefore, any imbalance in protein that automatically affect sperm physiology and fertility status. This review sheds a comprehensive and critical view on the significant functions of semenogelin in fertilization. This review can open up advanced proteomics research on semenogelin towards unravelling molecular mechanisms in fertilization.

Hyaluronic Acid: Known for Almost a Century, but Still in Vogue

Hyaluronic acid (HA) has a special position among glycosaminoglycans. As a major component of the extracellular matrix (ECM). This simple, unbranched polysaccharide is involved in the regulation of various biological cell processes, whether under physiological conditions or in cases of cell damage. This review summarizes the history of this molecule’s study, its distinctive metabolic pathway in the body, its unique properties, and current information regarding its interaction partners. Our main goal, however, is to intensively investigate whether this relatively simple polymer may find applications in protecting against ionizing radiation (IR) or for therapy in cases of radiation-induced damage. After exposure to IR, acute and belated damage develops in each tissue depending upon the dose received and the cellular composition of a given organ. A common feature of all organ damage is a distinct change in composition and structure of the ECM. In particular, the important role of HA was shown in lung tissue and the variability of this flexible molecule in the complex mechanism of radiation-induced lung injuries. Moreover, HA is also involved in intermediating cell behavior during morphogenesis and in tissue repair during inflammation, injury, and would healing. The possibility of using the HA polymer to affect or treat radiation tissue damage may point to the missing gaps in the responsible mechanisms in the onset of this disease. Therefore, in this article, we will also focus on obtaining answers from current knowledge and the results of studies as to whether hyaluronic acid can also find application in radiation science.

Disruption of Hyaluronic Acid in Skeletal Muscle Induces Decreased Voluntary Activity via Chemosensitive Muscle Afferent Sensitization in Male Mice

PEGPH20, a human recombinant hyaluronidase, has been proposed as a coadjutant to pancreatic cancer chemotherapy. In early trials, patients reported increased widespread muscle pain as the main adverse reaction to PEGPH20. To understand how PEGPH20 caused musculoskeletal pain, we systemically administered PEGPH20 to male mice and measured voluntary wheel activity and pain-related behaviors. These were paired with ex vivo electrophysiology of primary sensory neurons, whole DRG real-time PCR, and immunohistochemistry of hindpaw muscle. PEGPH20 induced significantly lower wheel running, compared with vehicle-treated animals, and decreased mechanical withdrawal thresholds 5 d after PEGPH20 injections. Chemo-sensory muscle afferents showed increased responses to noxious chemical stimulation of their receptive fields (RFs) in the PEGPH20-treated group. This was correlated with upregulation of the NGF receptor TrkA, the transient receptor potential vanilloid type 1 (TRPV1) channel and ATP-sensitive channel P2X3 in the DRG. Immunohistochemistry of hindpaw muscles revealed damage to the muscle architecture and extensive infiltration of the tissue by cells of the myelomonocytic lineage 3 d after PEGPH20 injection. Peripheral macrophage ablation in macrophage Fas-induced apoptosis (MaFIA) mice, however, did not prevent the decreased voluntary activity and instead caused even lower levels of running. These results suggest that disruption of hyaluronic acid (HA) within the muscle extracellular matrix (ECM) sensitizes chemo-nociceptive muscle afferents possibly leading to altered pain-like behaviors. Ablation experiments suggest macrophages are necessary for adequate recovery of voluntary activity after HA disruption. These data support a role for HA and macrophages in tissue integrity and muscle pain development in patients taking PEGPH20.

Site-specific integration as an efficient method for production of recombinant human hyaluronidase PH20 in semi-adherent cells

PH20 is a hyaluronidase enzyme that can hydrolyze the glycosidic bond in hyaluronic acid as the major proteoglycan found in extracellular matrices. In the present study, we constructed and characterized two donor plasmids, one of them with one and the second with two PH20 expression cassettes. The expression vectors were site specifically integrated into the genome of HEK293T cells using PhiC31 integrase system to develop HEK293T stable cell lines secreting His-tagged recombinant human PH20 (rhPH20) in the culture supernatant. The produced rhPH20 was quantified using ELISA and turbidimetric assay tests, and its catalytic activity was also assessed by treating the mouse cumulus-oocyte complexes. Our results showed that the secreted rhPH20 in the culture supernatant had the specific activity of 16,660 IU/mg and the recombinant enzyme was able to remove the cumulus cells from oocytes. The results also indicated that phiC31 enzyme inserted the PH20-expressing donor vectors into the specific pseudo attP sites including 10q21.2 and 20q11.22 in the genome of the target cells with different copy numbers. Taken together, our findings demonstrate that PhiC31 integrase system is able to be applied as a robust tool for efficient production and secretion of soluble and active rhPH20 by HEK293T cells as a semi-adherent human cell line. KEY POINTS: • Efficient production of human recombinant PH20 in a semi-adherent human cell line • Successful application of PhiC31 integrase system for generation of stable recombinant clones • Use of a human cell line for expression of a recombinant human protein due to complex and efficient post-translational modifications and protein folding.

Peperomia pellucida (L.) Kunth and eye diseases: A review on phytochemistry, pharmacology and toxicology

Peperomia pellucida (L.) Kunth is a medicinal plant used to manage inflammatory illnesses such as conjunctivitis, and gastrointestinal and respiratory tract disorders in tropical and subtropical regions. However, little is known about its pharmacological mechanism of action against eye diseases. This review aims to critically discuss the phytochemistry, pharmacology and toxicology of P. pellucida as well as its roles in the treatment of cataract, glaucoma and diabetic retinopathy. Recent developments in the uses of P. pellucida for healthcare and nutraceutical products by the pharmaceutical industry are also covered in this review. For this review, a literature search was performed with PubMed, ScienceDirect, SciFinder Scholar and Scopus databases, using relevant keywords. Among the various phytochemicals identified from P. pellucida, β-caryophyllene, carotol, dillapiole, ellagic acid, pellucidin A, phytol and vitexin exhibit strong pharmacological activities within the mitogen-activated protein kinase and nuclear factor-κB signalling pathways in inflammatory eye diseases. The antihypertensive, anti-inflammatory, antioxidant, antihyperglycemic and anti-angiogenic activities displayed by P. pellucida extracts in many in vitro, in vivo and clinical studies suggest its potential role in the management of inflammatory eye diseases. P. pellucida extract was non-toxic against normal cell lines but displayed mild toxicity in animal models. The growing public interest in P. pellucida has inspired the nutraceutical and pharmaceutical industries to process the plant into health products. Although the potential pharmacological mechanisms against eye diseases have been summarized, further studies of the interactions among constituent phytochemicals from P. pellucida within various signalling pathways shall support the use of the plant as an alternative therapeutic source.

Smart/stimuli-responsive hydrogels: Cutting-edge platforms for tissue engineering and other biomedical applications

Recently, biomedicine and tissue regeneration have emerged as great advances that impacted the spectrum of healthcare. This left the door open for further improvement of their applications to revitalize the impaired tissues. Hence, restoring their functions. The implementation of therapeutic protocols that merge biomimetic scaffolds, bioactive molecules, and cells plays a pivotal role in this track. Smart/stimuli-responsive hydrogels are remarkable three-dimensional (3D) bioscaffolds intended for tissue engineering and other biomedical purposes. They can simulate the physicochemical, mechanical, and biological characters of the innate tissues. Also, they provide the aqueous conditions for cell growth, support 3D conformation, provide mechanical stability for the cells, and serve as potent delivery matrices for bioactive molecules. Many natural and artificial polymers were broadly utilized to design these intelligent platforms with novel advanced characteristics and tailored functionalities that fit such applications. In the present review, we highlighted the different types of smart/stimuli-responsive hydrogels with emphasis on their synthesis scheme. Besides, the mechanisms of their responsiveness to different stimuli were elaborated. Their potential for tissue engineering applications was discussed. Furthermore, their exploitation in other biomedical applications as targeted drug delivery, smart biosensors, actuators, 3D and 4D printing, and 3D cell culture were outlined. In addition, we threw light on smart self-healing hydrogels and their applications in biomedicine. Eventually, we presented their future perceptions in biomedical and tissue regeneration applications. Conclusively, current progress in the design of smart/stimuli-responsive hydrogels enhances their prospective to function as intelligent, and sophisticated systems in different biomedical applications.

Comparative evaluation of efficacy of Physics Forceps versus conventional forceps in pediatric dental extractions: a prospective randomized study

BACKGROUND

This study aimed to determine the efficacy of Physics Forceps in pediatric dental extractions.

METHODS

This was a double-blind, randomized controlled trial with a parallel-arm design and identical allocation ratio (1:1). Children (n=104) were randomly divided into two groups for extraction of mandibular primary teeth (group I: Physics Forceps; group II: conventional forceps). The outcome variables assessed in the study were the time taken for extraction, pre- and postoperative anxiety (using RMS pictorial scale), incidence of fractured teeth, and postoperative pain on the first and third days (using the Wong-Baker faces pain scale).

RESULTS

A significant reduction (P < 0.001) in intraoperative time, anxiety, and incidence of tooth fracture was confined to group I. The pain significantly reduced from the first to the third postoperative day in both groups, but the mean reduction in RMS scores in the physics forceps group was far better than that in the conventional forceps group.

CONCLUSION

Physics Forceps aid in extraction of primary teeth with minimal trauma to supporting structures, as well as reducing anxiety in the pediatric population.

β-elimination of hyaluronate by red king crab hyaluronidase

Crustacean hyaluronidases are poorly understood both in terms of their enzymatic properties and in terms of their structural features. In this work, we show that the hepatopancreas homogenate of the red king crab has a hyaluronidase activity that is an order of magnitude higher than its commercial counterpart. Zymography revealed that the molecular weight of a protein with hyalorunidase activity is 40-50 kDa. Analysis of the hepatopancreas transcriptome and results of cloning and sequencing of cDNA revealed a hyaluronidase sequence with an expected molecular weight of 42.5 kDa. Further analysis showed that hyaluronat enzymatic cleavage follows the [Formula: see text]-elimination mechanism, which is well known for bacterial hyaluronidases. The results of ion-exchange chromatography showed that the final product of hyaluronate degradation is unsaturated tetrasaccharide. Thus, we identified a new hyaluronidase of higher eukaryotes, which is not integrated into the modern classification of hyaluronidases.

Phenol-Hyaluronic Acid Conjugates: Correlation of Oxidative Crosslinking Pathway and Adhesiveness

Hyaluronic acid (HA) is a natural polysaccharide with great biocompatibility for a variety of biomedical applications, such as tissue scaffolds, dermal fillers, and drug-delivery carriers. Despite the medical impact of HA, its poor adhesiveness and short-term in vivo stability limit its therapeutic efficacy. To overcome these shortcomings, a versatile modification strategy for the HA backbone has been developed. This strategy involves tethering phenol moieties on HA to provide both robust adhesiveness and intermolecular cohesion and can be used for oxidative crosslinking of the polymeric chain. However, a lack of knowledge still exists regarding the interchangeable phenolic adhesion and cohesion depending on the type of oxidizing agent used. Here, we reveal the correlation between phenolic adhesion and cohesion upon gelation of two different HA–phenol conjugates, HA–tyramine and HA–catechol, depending on the oxidant. For covalent/non-covalent crosslinking of HA, oxidizing agents, horseradish peroxidase/hydrogen peroxide, chemical oxidants (e.g., base, sodium periodate), and metal ions, were utilized. As a result, HA–catechol showed stronger adhesion properties, whereas HA–tyramine showed higher cohesion properties. In addition, covalent bonds allowed better adhesion compared to that of non-covalent bonds. Our findings are promising for designing adhesive and mechanically robust biomaterials based on phenol chemistry.

Hyaluronidases and hyaluronate lyases: From humans to bacteriophages

Hyaluronan is a non-sulfated negatively-charged linear polymer distributed in most parts of the human body, where it is located around cells in the extracellular matrix of connective tissues and plays an essential role in the organization of tissue architecture. Moreover, hyaluronan is involved in many biological processes and used in many clinical, cosmetic, pharmaceutic, and biotechnological applications worldwide. As interest in hyaluronan applications increases, so does interest in hyaluronidases and hyaluronate lyases, as these enzymes play a major part in hyaluronan degradation. Many hyaluronidases and hyaluronate lyases produced by eukaryotic cells, bacteria, and bacteriophages have so far been described and annotated, and their ability to cleave hyaluronan has been experimentally proven. These enzymes belong to several carbohydrate-active enzyme families, share very low sequence identity, and differ in their cleaving mechanisms and in their structural and functional properties. This review presents a summary of annotated and characterized hyaluronidases and hyaluronate lyases isolated from different sources belonging to distinct protein families, with a main focus on the binding and catalytic residues of the discussed enzymes in the context of their biochemical properties. In addition, the application potential of individual groups of hyaluronidases and hyaluronate lyases is evaluated.

Effects of Carissa carandas Linn. Fruit, Pulp, Leaf, and Seed on Oxidation, Inflammation, Tyrosinase, Matrix Metalloproteinase, Elastase, and Hyaluronidase Inhibition

In this study, the potential of Carissa carandas Linn. as a natural anti-aging, antioxidant, and skin whitening agent was studied. Various parts of C. carandas, including fruit, leaf, seed, and pulp were sequentially extracted by maceration using n-hexane, ethyl acetate, and ethanol, respectively. High-performance liquid chromatography, Folin–Ciocalteu, and Dowd method were used to investigate their chemical compositions. The inhibitory activities of oxidation process, matrix metalloproteinases (MMPs), elastase, hyaluronidase, and tyrosinase were analyzed. Cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay in a human epidermal keratinocyte line (HaCaT). The results exhibited that ethyl acetate could extract the most ursolic acid from C. carandas, while ethanol could extract the most phenolics and flavonoids. The leaf extract had the highest content of ursolic acid, phenolics, and flavonoids. The leaf extracted with ethyl acetate (AL) had the highest ursolic acid content (411.8 mg/g extract) and inhibited MMP-1, NF-kappa B, and tyrosinase activity the most. Ursolic acid has been proposed as a key component in these biological activities. Although several C. carandas extracts are beneficial to human skin, AL has been proposed for use in cosmetics and cosmeceuticals due to its superior anti-wrinkle, anti-inflammation, and whitening properties.