Termo de consentimento livre e esclarecido e sua relação com os procedimentos de preenchimento labial / Free and informed consent terms and its relationship with lip filling procedures

Introdução: Na medida em que envelhecemos os lábios estreitam-se, ocasionando perda de volume e contorno e como forma de minimizar este efeito fisiológico o preenchimento labial de escolha utilizado é o ácido hialurônico. É possível perceber efeitos adversos advindos do emprego deste material, e pelo fato da informação ao paciente ser assegurada pelo Código de Defesa do Consumidor e pelo fato da necessidade dos Cirurgiões-Dentistas terem de esclarecer seus pacientes, o Termo de Consentimento Livre e Esclarecido tornase necessário. Objetivo: identificar, por meio de aplicação de questionário, a percepção de profissionais que trabalham com Harmonização Orofacial em relação a necessidade do emprego do Termo de Consentimento Livre e Esclarecido (TCLE). O questionário apresentou 6 perguntas objetivas, que foram disponibilizadas na plataforma Google Forms®. Material e Método: os dados obtidos foram tabulados em uma planilha eletrônica do programa Microsoft Excel e após analisados descritivamente através de tabelas de frequência, porcentagens e gráficos estatísticos. Resultados: dentre os entrevistados foi constatado que a maioria, 87,5% dos especialistas em Harmonização Orofacial realizam o procedimento de preenchimento labial em sua rotina clínica, e 12,5% não. Conclusão: no presente estudo identificamos que os especialistas realizam o emprego do TCLE, em sua maioria, porém, alguns destes ainda negligenciam o seu uso(AU)

Introduction: As we age, the lips become thinner and to minimize this effect, the lip filler used is hyaluronic acid. It is possible to notice adverse effects arising from the use of this material, and it is extremely important that Dental Surgeons have to clarify their patients, the Free and Informed Consent Form becomes necessary. Objective: to identify, through the application of a questionnaire, the perception of professionals who work with Orofacial Harmonization in relation to the need to use the Free and Informed Consent Form (TCLE). The questionnaire presented 6 objective questions, which were made available on the Google Forms® platform. Materials and Methods: the data obtained were tabulated in a Microsoft Excel spreadsheet and then analyzed descriptively using frequency tables, percentages and graphs. Results: among those interviewed, it was found that the majority, 87.5% of specialists in Orofacial Harmonization perform the lip filling procedure in their clinical routine, and 12.5% do not. With the high percentage of 59.4%, it was possible to verify that the majority of professionals perform 1 to 3 procedures per month; 31.3% perform 4 to 9 procedures per month; and 9.4% of 10 or more monthly procedures. Conclusion: in the present study it was possible to identify that the majority of specialists in Orofacial Harmonization use the informed consent form, however, some of them still neglect its use(AU)

In situ forming an injectable hyaluronic acid hydrogel for drug delivery and synergistic tumor therapy.

Stimulus-responsive injectable hydrogel has the key characteristics of in situ drug-loading ability and the controlled drug release, enabling efficient delivery and precise release of chemotherapy drugs at the tumor site, thereby being used as a local drug delivery system for sustained tumor treatment. This article designed a smart responsive injectable hydrogel loaded with anti-tumor drugs and nanoparticles to achieve efficient and specific synergistic treatment of tumors. Hyaluronic acid (HA) hydrogel obtained by cross-linking HA-SH (HS) and HA-Tyr (HT) through horseradish peroxidase (HRP), and doxorubicin hydrochloride (DOX) and folic acid-polyethylene glycol-amine (FA-PEG-NH2) modified PDA (denoted as PPF) were encapsulated to construct the HS/HT@PPF/D hydrogel. The hydrogel had good biocompatibility, injectability, and could respond to multiple stimuli at the tumor site, thereby achieving controlled drug release. At the same time, PPF gave it excellent photothermal efficiency, photothermal stability and tumor targeting. In vitro and in vivo experimental results showed that the HS/HT@PPF/D hydrogel combined with near-infrared laser irradiation could significantly improve its anti-tumor effect and could almost eliminate the entire tumor mass without obvious adverse reactions. The HS/HT@PPF/D hydrogel could achieve multi-stimulus-responsive drug delivery and be used for precise chemo-photothermal synergistic tumor treatment, thus providing a new platform for local synergistic tumor treatment.

Effective intravitreal gene delivery to retinal pigment epithelium with hyaluronic acid nanospheres.

Inherited retinal degeneration (IRD) can cause a wide range of different forms of vision loss and blindness, and in spite of extensive advancements in gene therapy research, therapeutic approaches for targeting IRDs are still lacking. We have recently developed an approach for the intravitreal co-delivery of hyaluronic-acid nanospheres (HA-NSs) with sulfotyrosine (ST), effectively reaching the outer retina from the vitreal cavity. Here, our goal was to understand whether DNA-filled HA-NSs could generate gene expression in the outer retina. TxRed-labeled HA-NSs were compacted with plasmid DNA carrying a GFP reporter gene and intravitreally injected into the mouse retina. Follow-up at 4 weeks showed widespread gene expression in the outer retina and reduced, albeit present, expression at 8 weeks post-injection. Further analysis revealed this expression to be largely localized to the retinal pigment epithelium (RPE). These data show that intravitreal delivery of HA-NSs is a promising non-viral platform for the delivery of therapeutic genes and can generate pan-tissue, persistent gene expression in the RPE.

Allergic Conjunctivitis Management: Update on Ophthalmic Solutions.

PURPOSE OF REVIEW: The aim of this review, is to present an updated revision of topical management of SAC and PAC, based on the available scientific evidence and focused on the impact of ophthalmic solution formulations on eye surface. RECENT FINDINGS: Physicians treating ocular allergy should be aware of tear film and tear film disruption in SAC and PAC, and how eye drop composition and additives affect the physiology of the allergic eye. Seasonal and perennial allergic conjunctivitis (SAC and PAC) are the most frequent causes of ocular allergy (OA), and both conditions are underdiagnosed and undertreated. SAC and PAC are immunoglobulin E (IgE)-mediated hypersensitivity reactions. The additional tear film disruption caused by the release of inflammatory mediators increases and exacerbates the impact of signs and symptoms and may trigger damage of the ocular surface. Comorbidities are frequent, and dry eye disease in particular must be considered. Clinical guidelines for the management of SAC and PAC recommend topical therapy with antihistamines, mast cells stabilizers or dualaction agents as first-line treatment, but care should be taken, as many medications contain other compounds that may contribute to ocular surface damage.

Mild preparation of hyaluronic acid/silk fibroin sponges by modified crosslinking method.

The composites composed of hyaluronic acid (HA) and silk fibroin (SF) exhibit great potential in diverse biomedical applications. However, the utilization of commercial crosslinkers such as 1,4-butanediol diglycidyl ether (BDDE) for crosslinking HA typically necessitates harsh conditions involving strong alkaline, which greatly limits its potential applications. In this study, a mild modified approach was developed to fabricate HA/SF blend sponges crosslinked by BDDE without alkaline conditions. The blend solutions were cryo-concentrated to induce crosslinking reactions. The mechanism of freezing crosslinking was elucidated by investigating the effects of ice crystal growth and HA molecular weight on the degree of crosslinking. The results revealed that HA achieved efficient crosslinking when its molecular weight exceeds 1000 kDa and freezing temperatures ranged from -40 °C to -20 °C. After introducing SF, multiple crosslinks were formed between SF and HA chains, producing water-stable porous sponges. The SEM results demonstrated that the introduction of SF effectively enhanced the interconnectivity between macropores through creating subordinate holes onto the pores wall. Raising the SF content significantly enhanced compression strength, resistance to enzymatic degradation and cell viability of blend sponges. This study provides a novel strategy for designing bioactive HA/SF blend sponges as substitutes for tissue repair and wound dressing.

Preparation of chitosan-hyaluronic acid microcapsules and its dynamic release behavior analysis in a 3D-printed microchannel system: Exploration and verification.

This research focuses on the challenges of efficiently constructing drug carriers and evaluating their dynamic release in vitro simulation. By using pickering emulsion and layer-by-layer self-assembly methods. The microcapsules had tea tree oil as the core material, SiO2 nanoparticles as stabilizers, and chitosan and hyaluronic acid as shell materials. The microencapsulation mechanism, as well as the effects of core-shell mass ratio and stirring, were discussed. Specifically, a dynamic circulation simulation microchannel system was designed and manufactured based on 3D printing technology. In this simulation system, the release rate of microcapsules is accelerated and the trend changes, with its behavior aligning with the Boltzmann model. The study demonstrates the advantages of self-assembled inorganic-organic drug-loaded microcapsules in terms of controllable fabrication and ease of functional modification, and shows the potential of 3D printed cyclic microchannel systems in terms of operability and simulation fidelity in drug and physiological analysis.

Hyaluronic acid as a pulpotomy material in primary molars: an up to 30 months retrospective study.

BACKGROUND: The aim of this retrospective study was to determine the long-term clinical and radiographic success of our previous randomized clinical trial and to compare the success of hyaluronic acid, with the widely used formocresol and ferric sulphate agents. METHODS: This retrospective study is the extension of the 1-year survey of our randomized clinical trial that had compared the effectiveness of a hyaluronic acid pulpotomy over formocresol and ferric sulphate pulpotomies and included clinical and radiographic evaluations with a follow-up period of over 24 months for 44 children who applied to our clinic between May 2019 and September 2019. Long-term clinical and radiographic data were obtained from the periodic files of our department, wherein each tooth's file was examined to identify any clinical and radiographic findings. Descriptive statistics and Pearson's chi-square tests were used to evaluate the data. Statistical significance was considered as p < 0.05. RESULTS: The clinical and radiographic success rates of the hyaluronic acid, formocresol, and ferric sulphate groups were not statistically different at > 24 months. None of the teeth in the hyaluronic acid group showed any clinical findings at > 24 months. CONCLUSIONS: Hyaluronic acid pulpotomies exhibited comparable success rates to formocresol and ferric sulphate materials spanning over 24 months examinations. Because of convenient accessibility and applicability of hyaluronic acid, it may be recommended as a promising alternative medicament for pulpotomy treatments of primary molars. However, further long-term follow-up human studies are needed to better understand the effect of hyaluronic acid on the dental pulp of human primary molars.

Early periodontal wound healing after chlorhexidine rinsing: a randomized clinical trial.

OBJECTIVES: This single-center randomized, parallel design, clinical trial with a 2-week follow-up involved patients affected by periodontitis undergoing periodontal surgery. The aim was to evaluate periodontal surgical wound healing with the use of chlorhexidine-based mouth rinses versus an untreated control group. MATERIALS AND METHODS: Periodontal surgery was performed following a standardized protocol. Patients were randomly prescribed i) chlorhexidine (CHX) + anti-discoloration system (ADS) + hyaluronic acid (HA), ii) CHX + ADS or iii) no treatment (control group). Plaque score, gingival inflammation, and Early Healing Index (EHI), assessing the degree of wound closure and the presence of fibrin and necrosis, were evaluated at 3, 7 and 14 days after surgery. RESULTS: In total, 33 patients were enrolled. Patients were comparable at baseline for all measured clinical parameters. At 3-days wound healing was significantly improved in all patients treated with CHX + ADS-based mouth rinses with a lower EHI score at the interdental papillae compared with control group (p < 0.01). CHX + ADS + HA group presented improved healing across all time points in terms of EHI, plaque containment, and gingival inflammation when compared to control group (p < 0.01). CONCLUSIONS: The usage of CHX-ADS following periodontal surgery improved early wound healing, reduced plaque accumulation and gingival inflammation. During the early post-operative period the adjunct of HA further improved soft tissue closure. CLINICAL RELEVANCE: This study aims at evaluating the response of gingival tissues to mouth rinsing with chlorhexidine and anti-discoloration system (CHX + ADS) or CHX + ADS + hyaluronic acid (CHX + ADS + HA) versus no rinse in terms of healing of the periodontal surgical wound. CHX + ADS mouth rinses enhanced early soft tissue closure after periodontal surgery and contributed to the reduction in plaque accumulation and gingival inflammation. The adjunct of HA may be beneficial especially in the early post-operative period. CHX + ADS administration following periodontal surgery may improve soft tissue healing in the first two post-operative weeks.

Fabrication and characteristics of multifunctional hydrogel dressings using dopamine modified hyaluronic acid and phenylboronic acid modified chitosan.

The healing of damaged skin is a complex and dynamic process, and the multi-functional hydrogel dressings could promote skin tissue healing. This study, therefore, explored the development of a composite multifunctional hydrogel (HDCP) by incorporating the dopamine modified hyaluronic acid (HA-DA) and phenylboronic acid modified chitosan (CS-PBA) crosslinked using boric acid ester bonds. The integration of HA-DA and CS-PBA could be confirmed using the Fourier transform infrared spectrometer and 1H nuclear magnetic resonance analyses. The fabricated HDCP hydrogels exhibited porous structure, elastic solid behavior, shear-thinning, and adhesion properties. Furthermore, the HDCP hydrogels exhibited antibacterial efficacy against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). Subsequently, the cytocompatibility of the HDCP hydrogels was verified through CCK-8 assay and fluorescent image analysis following co-cultivation with NIH-3T3 cells. This research presents an innovative multifunctional hydrogel that holds promise as a wound dressing for various applications within the realm of wound healing.

Effectiveness of topical hyaluronic acid of different molecular weights in xerosis cutis treatment in elderly: a double-blind, randomized controlled trial.

Dry skin is a common dermatological condition that frequently affects the elderly. A contributing cause to dry skin is a reduced concentration of hyaluronic acid (HA) in both the epidermis and dermis. The effectiveness of moisturizer containing HA as a therapy for dry skin is impacted by its specific molecular weight. Low molecular weight HA (LMWHA) is believed to be more effective in replenishing skin hydration in aging skin compared to High Molecular Weight HA (HMWHA) due to its ability to penetrate the stratum corneum. However, there is a lack of clinical research supporting this claim. A double-blind, randomized controlled trial was conducted on 36 residents of a nursing home in Jakarta. The participants, aged between 60 and 80 years, had been diagnosed with dry skin. Each test subject was administered three distinct, randomized moisturizing lotions (LMWHA, HMWHA, or vehicle), to be topically applied to three separate sites on the leg. Skin capacitance (SCap), transepidermal water loss (TEWL), and specified symptom sum score (SRRC) were measured at weeks 0, 2, and 4. After four weeks of therapy, area that was treated with LMWHA showed greater SCap values compared to the area treated with HMWHA (56.37 AU vs. 52.37 AU, p = 0.004) and vehicle (56.37 AU vs. 49.01 AU, p < 0.001). All groups did not show any significant differences in TEWL and SRRC scores. No side effects were found in all groups. The application of a moisturizer containing LMWHA to the dry skin of elderly resulted in significant improvements in skin hydration compared to moisturizers containing HMWHA and vehicle. Furthermore, these moisturizers demonstrated similar safety in treating dry skin in the elderly. ClinicalTrials.gov Identifier NCT06178367, https://clinicaltrials.gov/study/NCT06178367 .

A quality by design approach to optimise disulfide-linked hyaluronic acid hydrogels.

In this study, the disulfide-linked hyaluronic acid (HA) hydrogels were optimised for potential application as a scaffold in tissue engineering through the Quality by Design (QbD) approach. For this purpose, HA was first modified by incorporating the cysteine moiety into the HA backbone, which promoted the formation of disulfide cross-linked HA hydrogel at physiological pH. Utilising a Design of Experiments (DoE) methodology, the critical factors to achieve stable biomaterials, i.e. the degree of HA substitution, HA molecular weight, and coupling agent ratio, were explored. To establish a design space, the DoE was performed with 65 kDa, 138 kDa and 200 kDa HA and variable concentrations of coupling agent to optimise conditions to obtain HA hydrogel with improved rheological properties. Thus, HA hydrogel with a 12 % degree of modification, storage modulus of ≈2321 Pa and loss modulus of ≈15 Pa, was achieved with the optimum ratio of coupling agent. Furthermore, biocompatibility assessments in C28/I2 chondrocyte cells demonstrated the non-toxic nature of the hydrogel, underscoring its potential for tissue regeneration. Our findings highlight the efficacy of the QbD approach in designing HA hydrogels with tailored properties for biomedical applications.

Stretchable hydrogels of chitosan/hyaluronic acid induced by polyelectrolyte complexation around neutral pH.

In this work, we propose the formation of stretchable hydrogels at neutral pH from the physical crosslinking of chitosan (CS) and hyaluronic acid (HA) by polyelectrolyte complexation. A mixture of CS (Mw ≈ 600 kg/mol, degree of acetylation ≈ 50 %) solution and HA (Mw ≈ 77 kg/mol) solution was prepared with an excess of salts screening the electrostatic interactions CS/HA. In a controlled manner, the polyelectrolyte complexation was induced through the progressive dialysis of the salted polymer mixture against a sodium acetate solution (AcONa, 0.01 M) for 7 days. Depending on [HA], various materials were obtained: viscous solutions at [HA] = 0.75 % (w/v); hydrogels at [HA] = 1.50-2.24 % (w/v) with Young modulus of 14 kPa and stretchable to 200 %. The small angle X-ray scattering characterization of the hydrogels revealed a multiscale organization related to the conformation of the polymers induced by the physical interactions. The dialysis process with AcONa was optimized by adding a dialysis step against a zinc acetate solution containing Zn2+. The combination of polyelectrolyte complexation between CS/HA and metal complexation between Zn2+ and the polymers led to an enhancement of the hydrogel stretchability up to 400 %.

Biofunctionalized hydrogel composed of genipin-crosslinked gelatin/hyaluronic acid incorporated with lyophilized platelet-rich fibrin for segmental bone defect repair.

Segmental bone defects can arise from trauma, infection, metabolic bone disorders, or tumor removal. Hydrogels have gained attention in the field of bone regeneration due to their unique hydrophilic properties and the ability to customize their physical and chemical characteristics to serve as scaffolds and carriers for growth factors. However, the limited mechanical strength of hydrogels and the rapid release of active substances have hindered their clinical utility and therapeutic effectiveness. With ongoing advancements in material science, the development of injectable and biofunctionalized hydrogels holds great promise for addressing the challenges associated with segmental bone defects. In this study, we incorporated lyophilized platelet-rich fibrin (LPRF), which contains a multitude of growth factors, into a genipin-crosslinked gelatin/hyaluronic acid (GLT/HA-0.5 % GP) hydrogel to create an injectable and biofunctionalized composite material. Our findings demonstrate that this biofunctionalized hydrogel possesses optimal attributes for bone tissue engineering. Furthermore, results obtained from rabbit model with segmental tibial bone defects, indicate that the treatment with this biofunctionalized hydrogel resulted in increased new bone formation, as confirmed by imaging and histological analysis. From a translational perspective, this biofunctionalized hydrogel provides innovative and bioinspired capabilities that have the potential to enhance bone repair and regeneration in future clinical applications.

Function and contribution of two putative Enterococcus faecalis glycosaminoglycan degrading enzymes to bacteremia and catheter-associated urinary tract infection.

Enterococcus faecalis is a common cause of healthcare-acquired bloodstream infections and catheter-associated urinary tract infections (CAUTIs) in both adults and children. Treatment of E. faecalis infection is frequently complicated by multi-drug resistance. Based on protein homology, E. faecalis encodes two putative hyaluronidases, EF3023 (HylA) and EF0818 (HylB). In other Gram-positive pathogens, hyaluronidases have been shown to contribute to tissue damage and immune evasion, but the function in E. faecalis has yet to be explored. Here, we show that both hylA and hylB contribute to E. faecalis pathogenesis. In a CAUTI model, ΔhylA exhibited defects in bladder colonization and dissemination to the bloodstream, and ΔhylB exhibited a defect in kidney colonization. Furthermore, a ΔhylAΔhylB double mutant exhibited a severe colonization defect in a model of bacteremia while the single mutants colonized to a similar level as the wild-type strain, suggesting potential functional redundancy within the bloodstream. We next examined enzymatic activity, and demonstrate that HylB is capable of digesting both hyaluronic acid (HA) and chondroitin sulfate in vitro, while HylA exhibits only a very modest activity against heparin. Importantly, HA degradation by HylB provided a modest increase in cell density during the stationary phase and also contributed to dampening of lipopolysaccharide-mediated NF-κB activation. Overall, these data demonstrate that glycosaminoglycan degradation is important for E. faecalis pathogenesis in the urinary tract and during bloodstream infection.

Hyaluronic acid-poly(glyceryl)10-stearate nanoemulsion for co-delivery of fish oil and resveratrol: Enhancing bioaccessibility and antioxidant potency.

Hyaluronic acid (HA), an endogenous polysaccharide comprising alternating D-glucuronic acid and N-acetylglucosamine units, is renowned for its high hydrophilicity, biocompatibility, and biodegradability. These attributes have rendered HA invaluable across medical and drug delivery fields. HA can be altered through physical, chemical, or enzymatic methods to improve the properties of the modified substances. In this work, we synthesized a derivative via the esterification of HA with poly(glyceryl)10-stearate (PG10-C18), designated as HA-PG10-C18. This novel derivative was employed to fabricate a nano co-delivery system (HA-PG10-C18@Res-NE) for fish oil and resveratrol (Res), aiming to enhance their stability and bioaccessibility. An exhaustive investigation of HA-PG10-C18@Res-NE revealed that the HA-modified system displayed superior physicochemical stability, notably in withstanding oxidation and neutralizing free radicals. Moreover, in vitro simulated digestion underscored the system's enhanced bioaccessibility of Res and more efficient release of free fatty acids. These outcomes underscore the strategic advantage of HA in modifying PG10-C18 for nanoemulsion formulation. Consequently, HA-PG10-C18 stands as a promising emulsifier for encapsulating lipophilic bioactives in functional foods, nutraceuticals, and pharmaceuticals.

On the design of lignin reinforced acrylic acid/hyaluronic acid adhesive hydrogels with conductive PEDOT:HA nanoparticles.

Hydrogels are of great importance in biomedical engineering. They possess the ability to mimic bodily soft tissues, and this allows exciting possibilities for applications such as tissue engineering, drug delivery and wound healing, however much work remains on stability and mechanical robustness to allow for translation to clinical applications. The work herein describes the synthesis and analysis of a biocompatible, versatile hydrogel that has tailorable swelling, high stability when swollen and thermal stability. The synthesis methods used produce a hydrogel with high elasticity, good mechanical properties and rapid crosslinking whilst displaying biocompatibility, adhesion, and conductivity. It has been shown that cell viability in the samples is above 80 % in all cases, a Young's Modulus of up to 85 kPa and high swelling degrees were achieved. These materials show potential for use in numerous applications such as adhesive sensors, skin grafts and drug delivery systems.

Carbene-mediated gelatin and hyaluronic acid hydrogel paints with ultra adhesive ability for arthroscopic cartilage repair.

In articular cartilage defect, particularly in arthroscopy, regenerative hydrogels are urgently needed. It should be able to firmly adhere to the cartilage tissue and maintain sufficient mechanical strength to withstand approximately 10 kPa of arthroscopic hydraulic flushing. In this study, we report a carbene-mediated ultra adhesive hybrid hydrogel paints for arthroscopic cartilage repair, which combined the photo initiation of double crosslinking system with the addition of diatomite, as a further reinforcing agent and biological inorganic substances. The double network consisting of ultraviolet initiated polymerization of hyaluronic acid methacrylate (HAMA) and carbene insertion chemistry of diazirine-grafted gelatin (GelDA) formed an ultra-strong adhesive hydrogel paint (H2G5DE). Diatomite helped the H2G5DE hydrogel paint firmly adhere to the cartilage defect, withstanding nearly 100 kPa of hydraulic pressure, almost 10 times that in clinical arthroscopy. Furthermore, the H2G5DE hydrogel supported cell growth, proliferation, and migration, thus successfully repairing cartilage defects. Overall, this study demonstrates a proof-of-concept of ultra-adhesive polysaccharide hydrogel paints, which can firmly adhere to the articular cartilage defects, can resist continuous hydraulic pressure, can promote effective cartilage regeneration, and is very suitable for minimally invasive arthroscopy.

Dual fluorescence response of calix[4]arene-1,8-naphthalimide derivatives towards Hg(II) /Cr(VI) and their antimicrobial studies of transparent biofilms with hyaluronic acid.

In this study, 4-sulfo-1,8-naphthalimide calixarene of derivatives were prepared (3 and 4) then transparent biofilms of the Ag salts of these compounds were formed in the presence of hyaluronic acid (HA), and antimicrobial properties were investigated. In chemosensor studies, the sensing ability behavior of 3 and 4 towards some cations and anions was investigated by fluorescence spectroscopy. It was observed that the prepared chemosensors show selectivity towards Hg(II) and Cr(VI). Ligand-ion interaction occurs according to the photo-induced electron transfer (PET) mechanism. The stoichiometric ratio was calculated by using Stern-Volmer plot method and binding constant Ksv values were found as 5.2 × 107 M-1 and 5.5 × 107 M-1 for 3-Hg(II) and 4-Hg(II) complexes, respectively and 4.0 × 107 M-1 and 4.3 × 107 M-1 for 3-Cr(VI) and 4-Cr(VI) complexes. The detection limits of the complexes of 3-Hg(II) and 4-Hg(II) are 6.35 × 10-12and 6.81 × 10-12, while those of 3-Cr(VI) and 4-Cr(VI) are 1.41 × 10- 11and 8.37 × 10-12, respectively. As a result of the antimicrobial test performed with these compounds, it was observed that the most effective material was HA-3Ag, which showed a significant antibacterial effect against Sarcina lutea (S. lutea) at a minimum inhibitory concentration (MIC) value of 0.097 mg/mL.

Hyaluronic acid nanoparticles for targeted oral delivery of doxorubicin: Lymphatic transport and CD44 engagement.

The oral delivery of doxorubicin (DOX), an anti-cancer drug, encounters multiple hurdles such as limited gastrointestinal permeability, P-glycoprotein-mediated efflux, brief intestinal residence, and rapid degradation. This study introduced a novel approach utilizing hyaluronic acid (HA)-grafted fatty acid monoglycerides (HGD) to encapsulate DOX, forming HGD-DOX nanoparticles, aimed at enhancing its oral bioavailability. Drug encapsulated by HGD provided several advantages, including extended drug retention in the gastrointestinal tract, controlled release kinetics, and promotion of lymphatic absorption in the intestine. Additionally, HGD-DOX nanoparticles could specifically target CD44 receptors, potentially increasing therapeutic efficacy. The uptake mechanism of HGD-DOX nanoparticles primarily involved clathrin-mediated, caveolin-mediated and macropinocytosis endocytosis. Pharmacokinetic analysis further revealed that HGD significantly prolonged the in vivo residence time of DOX. In vivo imaging and pharmacodynamic studies indicated that HGD possessed tumor-targeting capabilities and exhibited a significant inhibitory effect on tumor growth, while maintaining an acceptable safety profile. Collectively, these findings position HGD-DOX nanoparticles as a promising strategy to boost the oral bioavailability of DOX, offering a potential avenue for improved cancer treatment.

Hyaluronic acid/PEO electrospun tube reduces tendon adhesion to levels comparable to native tendons - An in vitro and in vivo study.

A major problem after tendon injury is adhesion formation to the surrounding tissue leading to a limited range of motion. A viable strategy to reduce adhesion extent is the use of physical barriers that limit the contact between the tendon and the adjacent tissue. The purpose of this study was to fabricate an electrospun bilayered tube of hyaluronic acid/polyethylene oxide (HA/PEO) and biodegradable DegraPol® (DP) to improve the anti-adhesive effect of the implant in a rabbit Achilles tendon full laceration model compared to a pure DP tube. Additionally, the attachment of rabbit tenocytes on pure DP and HA/PEO containing scaffolds was tested and Scanning Electron Microscopy, Fourier-transform Infrared Spectroscopy, Differential Scanning Calorimetry, Water Contact Angle measurements, and testing of mechanical properties were used to characterize the scaffolds. In vivo assessment after three weeks showed that the implant containing a second HA/PEO layer significantly reduced adhesion extent reaching levels comparable to native tendons, compared with a pure DP implant that reduced adhesion formation only by 20 %. Tenocytes were able to attach to and migrate into every scaffold, but cell number was reduced over two weeks. Implants containing HA/PEO showed better mechanical properties than pure DP tubes and with the ability to entirely reduce adhesion extent makes this implant a promising candidate for clinical application in tendon repair.