Incorporation Of Chlorhexidine Research Articles

Dual drug release profiles of salicylate-based polymers and encapsulated chlorhexidine as potential periodontitis treatments

Salicylate-based poly(anhydride-esters; SAPAEs) have demonstrated wound healing properties due to salicylic acid (SA) release during polymer degradation. Additionally, the polymers are deformable and self-adhesive due to their low Young’s modulus, lower glass transition temperature ( Tg), and inherent tackiness at body temperature. These properties make them particularly well-suited for therapeutic use in the bacteria-laden environment of the oral cavity. To enhance their therapeutic capabilities, the antiseptic chlorhexidine dihydrochloride was physically incorporated into SAPAEs for dual release of antiseptic and anti-inflammatory upon degradation. This study analyzes the thermomechanical properties of two SAPAE compositions (adipate homopolymer and 50:50 adipate:sebacate copolymer) and the release of chlorhexidine (incorporated at 10% (w/w)) from these polymers. Polymer adhesivity was monitored as a function of chlorhexidine incorporation and in vitro degradation time. Throughout in vitro degradation, the polymer systems had a low Young’s modulus and a Tg at or near body temperature. Incorporation of the antiseptic further decreased Young’s modulus and increased both the Tg and adhesivity. The release profiles were also evaluated and determined to be similar for the homopolymer and copolymer, although the homopolymer degradation occurred over a longer time period. Overall, the SAPAE systems have favorable properties for periodontal disease treatments by virtue of their controlled degradability, deformability, adhesivity, and release profiles with encapsulated antiseptic.

Development and Characterization of Nano-Chitosan-Polyvinyl Alcohol-Glycerol -Chlorhexidine Films for Wound Healing Applications

The process of wound healing is intricate and dynamic, requiring advanced medical care for a speedy recovery. Currently available semi-permeable wound dressings fall short in efficiently absorbing excess wound exudates to facilitate moist wound care, a crucial factor for promoting effective wound healing. Additionally, efforts have been made to enhance the antibacterial properties of wound dressings by incorporating antimicrobials into films. In this study, films were development using nanochitosan-polyvinyl alcohol-glycerol-chlorhexidine (NC-PVA-GLY-CLX) for applications in wound healing. The dressings were subjected to various characterizations, including UV-Visible spectrometry, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Thermogravimetric analysis, and X‑ray diffraction pattern. Furthermore, the resulting film dressings underwent evaluation for their bactericidal properties. The findings indicated that the incorporation of chlorhexidine into the films has positively influenced the fluid holding capacity and the active period of the dressing, creating a favourable environment for effective wound healing.

Development of nanobiosilicate, tricalcium phosphate and chlorhexidine materials for biomineralization with crystallographic similarity to hydroxyapatite and biomodified collagen

ObjectivesThe aim of this work is to test experimental cements, doped with a silicate based bioactive nanoparticle (NanoBiosilicate). Methods, we synthesized a glass nanoparticle by Sol-Gel Stöber method, used to be incorporated in a dental material for endodontic uses. Materials and methodsWe assess the mineralizing properties and biocompatibility. Besides the crystallography characterization of the resultant new crystals. Results, After analysis, and comparison with commercial materials, the material tested was similar in mechanical properties required by ISO, The ion release was effective after 2 hr. of setting and the novel material was cell compatible accepted by ISO. ResultsWe found new formed Calcium Phosphate peaks in the spectroscopic analysis (FTIR), remarkably the crystals formed were comparable to hydroxyapatite when analyzed with a Selected Area Electron Diffractometer, with rings of 2.84 Å for 002, and the 2.77 Å is also visible for 210. The 6.83 Å and 6.88 Å, for respective 222 and 004. The incorporation of Chlorhexidine was not detrimental for this property, Significance, the features mentioned represented a progress in biomineralization field that was associated to an improved mineral structure formation with increased crystallographic similarity to natural hydroxyapatite. When chlorhexidine was added a favorable biomodification of the remaining collagen in dentinal walls and antimicrobial activity potential were also observed.

BIOCOMPATIBLE AND ANTIMICROBIAL CELLULOSE ACETATE NANOFIBER MEMBRANE FROM BANANA (MUSA ACUMINATA X BALBISIANA) PSEUDOSTEM FIBERS FOR WOUND HEALING AND TISSUE ENGINEERING

Electrospun nanofiber membranes play a vital role in the biomedical field, especially for wound healing and tissue engineering applications. This study explored the development of biocompatible and antibacterial cellulose acetate electrospun nanofiber membranes prepared from banana pseudostem fibers. Cellulose rich dissolving pulp from alkali treated banana pseudostem fibers was subjected to esterification reaction to produce cellulose acetate. The synthesized cellulose acetate and chlorhexidine (CHX), an antimicrobial agent, were dissolved in 2:1 acetone:N,N-dimethylacetamide solvent and subsequently electrospun into a nanofiber membrane. FT-IR spectroscopy of the nanofiber confirmed the presence of cellulose acetate and the successful incorporation of CHX into the nanofibers. SEM imaging showed that the fiber diameter of the nanofiber membrane ranged from 200 nm to 300 nm. The MTT cytotoxicity assay and antimicrobial assay of nanofibers revealed that the nanofiber membrane with chlorhexidine concentration of 1.0 w/v was the optimum formulation as it achieved potent antimicrobial activity (zone of inhibition (ZOI): Escherichia coli – 18.38 mm and Staphylococcus aureus – 22.51 mm), while exhibiting low cytotoxicity to human intestinal epithelial cell line, HIEC-6 (percent cell inhibition: 13.07% and IC50: >100 μg/mL). The results indicated successful preparation of biocompatible and antimicrobial nanofiber membranes from banana pseudostem fiber with potential application in wound healing and tissue engineering.

Antibacterial and fluorescent clear aligner attachment resin modified with chlorhexidine loaded mesoporous silica nanoparticles and zinc oxide quantum dots

ObjectivesTo develop an antibacterial and fluorescent clear aligner attachment resin via the incorporation of chlorhexidine loaded pore-expanded mesoporous silica nanoparticles (CHX@pMSN) and amino-silane functionalized zinc oxide quantum dots (aZnOQDs), and to evaluate its antibacterial activity, fluorescence capability, esthetic properties, mechanical performance and biocompatibility. MethodsCHX@pMSN and aZnOQDs were incorporated into the commercial resin composites (Filtek Z350 XT, 3M) at different mass fractions, control group: Filtek; fluorescent attachment resin (FAR): Filtek + 3 wt% aZnOQDs; antibacterial and fluorescent attachment resin (AFAR)-1: Filtek + 3 wt% aZnOQDs + 1 wt% CHX@pMSN; AFAR-2: Filtek + 3 wt% aZnOQDs + 3 wt% CHX@pMSN; AFAR-3: Filtek + 3 wt% aZnOQDs + 5 wt% CHX@pMSN. CHX release, antibacterial activity, fluorescence capability, color change, stain resistance, degree of conversion, depth of cure, polymerization shrinkage, water sorption and solubility, softening in solvent, flexural strength, flexural modulus, shear bond strength, and cytotoxicity were evaluated comprehensively. ResultsCHX could be continuously released from the AFAR groups for up to 30 days. CFU, MTT, lactic acid production, SEM and CLSM evaluation showed AFAR-2 and AFAR-3 could effectively inhibit S. mutans biofilms even after 1-month aging. Only AFAR-3 showed clinically perceptible color change and all the experimental groups were not more susceptible to staining. AFAR-1 and AFAR-2 could suppress polymerization shrinkage and enhance the resistance to degradation without compromising other properties, including degree of conversion, water sorption and solubility, flexural strength, flexural modulus, and shear bond strength. Depth of cure of all the four experimental groups was significantly decreased (p < 0.05) but still within the ISO standard. CCK-8 assay and live/dead cell staining denied the cytotoxicity of experimental resins. Fluorescence intensity tests showed that FAR and AFAR-2 could emit strong yellowish fluorescence under the excitation of ultraviolet for up to six months. ConclusionsAFRA-2 possessed long-term antibiofilm activity, strong fluorescence capability and satisfying biocompatibility without compromising esthetic and mechanical properties. This study proposed a new strategy for reducing bacteria accumulation around the attachment, which is also promising in helping orthodontists to remove the attachment thoroughly and precisely.

Incorporation of chlorhexidine in self-adhesive resin cements.

The aim of this study was to evaluate the maximum amount of chlorhexidine (CHX) that could be incorporated to self-adhesive resin cements to add antibacterial effect without affecting the physical properties. The CHX was incorporated into a commercial self-adhesive resin cement at mass fractions of 0.5-15 wt%, and the CHX-release profile, antibacterial effect, flexural and bond strengths of experimental cements were evaluated. Increasing the CHX content from 5 to 15 wt% resulted in a higher released concentration of CHX. In agar diffusion tests, experimental cements containing 5, 10, and 15 wt% CHX produced inhibition zones against oral bacteria. In flexural strength and shear bond strength to dentin, no significant reduction was observed with the incorporation of 5 wt% CHX. This in vitro study suggests that the addition of 5 wt% CHX yielded an antibacterial self-adhesive cement and had no adverse effect on the flexural and shear bond strengths.

Photocrosslinkable methacrylated gelatin hydrogel as a cell-friendly injectable delivery system for chlorhexidine in regenerative endodontics

ObjectivesThis work sought to formulate photocrosslinkable chlorhexidine (CHX)-laden methacrylated gelatin (CHX/GelMA) hydrogels with broad spectrum of action against endodontic pathogens as a clinically viable cell-friendly disinfection therapy prior to regenerative endodontics procedures. MethodsCHX/GelMA hydrogel formulations were successfully synthesized using CHX concentrations between 0.12 % and 5 % w/v. Hydrogel microstructure was evaluated by scanning electron microscopy (SEM). Swelling and enzymatic degradation were assessed to determine microenvironmental effects. Compression test was performed to investigate the influence of CHX incorporation on the hydrogels’ biomechanics. The antimicrobial and anti-biofilm potential of the formulated hydrogels were assessed using agar diffusion assays and a microcosms biofilm model, respectively. The cytocompatibility was evaluated by exposing stem cells from human exfoliated deciduous teeth (SHEDs) to hydrogel extracts (i.e., leachable byproducts obtained from overtime hydrogel incubation in phosphate buffer saline). The data were analyzed using One- and Two-way ANOVA and Tukey’s test (α = 0.05). ResultsCHX/GelMA hydrogels were effectively prepared. NMR spectroscopy confirmed the incorporation of CHX into GelMA. The addition of CHX did not change the micromorphology (pore size) nor the swelling profile (p > 0.05). CHX incorporation reduced the degradation rate of the hydrogels (p < 0.001); whereas, it contributed to increased compressive modulus (p < 0.05). Regarding the antimicrobial properties, the incorporation of CHX showed a statistically significant decrease in the number of bacteria colonies at 0.12 % and 0.5 % concentration (p < 0.001) and completely inhibited the growth of biofilm at concentration levels 1 %, 2 %, and 5 %. Meanwhile, the addition of CHX, regardless of the concentration, did not lead to cell toxicity, as cell viability values were above 70 %. SignificanceThe addition of CHX into GelMA showed significant antimicrobial action against the pathogens tested, even at low concentrations, with the potential to be used as a cell-friendly injectable drug delivery system for root canal disinfection prior to regenerative endodontics.

Flexural strength and compressive strength of conventional glass ionomer luting cement and resin modified glass ionomer luting cement after incorporation of chlorhexidine

Introduction Glass ionomer luting cements (GIC) and Resin modified glass ionomer luting cements (RMGIC) are used to attach and seal fixed dental prostheses to teeth. Despite of their anticariogenic properties, there is still existence of caries. Studies have shown incorporation of chlorhexidine (CHX) can increase its antimicrobial action without affecting their physical properties. Objectives of the study The objective was to evaluate the effect of incorporation of CHX on flexural and compressive strength of conventional GIC and RMGIC. To compare the strength of both the cements on incorporation of CHX. Methodology: Forty bar shaped specimens and cylindrical specimens of both the cements were prepared for flexural strength and compressive strength testing using stainless steel mold. CHX powder was incorporated into experimental groups of both luting cements in a concentration of 1%. Specimens were stored in artificial saliva for 24 hours. Flexural strength and compressive strength of the specimens was determined using universal testing machine. Morphological evaluations for fractured surfaces were done using scanning electron microscopy. The data was statistically analyzed using independent sample t-test. Result: The results of the study showed that, addition of 1% CHX decreased compressive and flexural strength of both conventional GIC and RMGIC. On addition of CHX RMGIC showed better compressive and flexural strength compared to conventional GIC. Conclusions: The Chlorhexidine (CHX) amount should be kept below 1% for both the cements to sustain their strength.

PH-responsive silica nanoparticles for the treatment of skin wound infections

Chronic wounds are not only a burden for patients but also challenging for clinic treatment due to biofilm formation. Here, we utilized the phenomenon that chronic wounds possess an elevated local pH of 8.9 and developed pH-sensitive silica nanoparticles (SiNPs) to achieve a targeted drug release on alkaline wounds and optimized drug utility. Chlorhexidine (CHX), a disinfectant and antiseptic, was loaded into SiNPs as the model drug. The loaded CHX displayed a release 4 - 5 fold higher at pH 8.0 and 8.5 than at pH 6.5, 7.0 and 7.4. CHX-SiNPs furthermore exhibited a distinctive antibacterial activity at pH 8.0 and 8.5 against both Gram-negative and -positive bacterial pathogens, while no cytotoxicity was found according to cell viability analysis. The CHX-SiNPs were further formulated into alginate hydrogels to allow ease of use. The antibacterial efficacy of CHX-SiNPs was then studied with artificial wounds on ex vivo human skin. Treatment with CHX-SiNPs enabled nearly a 4-lg reduction of the viable bacterial cells, and the alginate formulated CHX-SiNPs led to almost a 3-lg reduction compared to the negative controls. The obtained results demonstrated that CHX-SiNPs are capable of efficient pH-triggered drug release, leading to high antibacterial efficacy. Moreover, CHX-SiNPs enlighten clinic potential towards the treatment of chronic wound infections. Statement of significanceA platform for controlled drug release at a relatively high pH value i.e., over 8, was established by tuning the physical structures of silica nanoparticles (SiNPs). Incorporation of chlorhexidine, an antimicrobial agent, into the fabricated SiNPs allowed a distinctive inhibition of bacterial growth at alkaline pHs, but not at acidic pHs. The efficacy of the SiNPs loaded with chlorhexidine in treating wound infections was further validated by utilizing ex vivo human skin samples. The presented work demonstrates clinic potential of employing alkaline pH as a non-invasive stimulus to achieve on-demand delivery of antimicrobials through SiNPs, showcasing a valuable approach to treating bacterial infections on chronic wounds.

Release characterization and biological effect of Glass Ionomer Functionalized with two different chlorohexidine derivatives: an in vitro study

Objective: To evaluate the effect of adding two different chlorohexidine derivatives; chlorhexidine hexametaphosphate and chlorhexidine digluconate to glass ionomer at three different concentrations (0.25%, 0.75%and 1.5%) regarding the antibacterial effect, chlorhexidine release and fluoride release. Methods: A total of 405 specimens were prepared and tested after 7 days, 3 months and 6 months of storage in distilled water (n=5).For testing antibacterial effect, chlorhexidine release and fluoride release, the mix was packed in a ready-made Split Teflon molds to obtain disc-shaped specimen with dimensions 10 mm in diameter and 2 mm thickness according to ISO standardizations. One-way ANOVA and One-way repeated measure ANOVA test were used for statistical analysis of data. Results: The incorporation of chlorhexidine into ChemFil Superior glass ionomer cement in both derivatives has high significance ability to provide a long-term antimicrobial effect on Streptococcus mutans and Lactobacillius acidophilus. The chlorhexidine release was increased by adding chlorhexidine in both derivatives to GIC than the unmodified Glass-ionomer cement for study duration. However, the fluoride release was decreased in the modified specimens than the original one. Conclusion: Addition of chlorhexidine enhanced the antibacterial effect of the glass ionomer and chlorhexidine release. However, fluoride release was reduced than original

In vitro evaluation of physicochemical properties of soft lining resins after incorporation of chlorhexidine

Statement of problemIncorporating chlorhexidine into soft lining materials has been suggested to reduce biofilm development on the material surface and treat denture stomatitis. However, evaluation of the physicochemical properties of this material is necessary. PurposeThe purpose of this in vitro study was to evaluate the physicochemical properties of resin-based denture soft lining materials modified with chlorhexidine diacetate (CDA). Material and methodsTwo soft lining resins were tested, one based on polymethyl methacrylate (PMMA) and the other on polyethyl methacrylate (PEMA), into which 0.5%, 1.0%, or 2.0% of CDA was incorporated; the control group had no CDA. The specimens were stored for 2 hours, 48 hours, 7, 14, 21, and 28 days and then analyzed for polymer crystallinity, Shore A hardness, degree of monomer conversion, residual monomer leaching, and CDA release. Data were analyzed by using a 3-way ANOVA and the Tukey HSD test (α=.05). ResultsThe polymer crystallinity of PEMA and PMMA did not change after CDA incorporation. Shore A hardness increased over time, but not for any CDA concentrations tested after 28 days (P>.05). Considering the degree of conversion, PMMA-based resin showed no statistically significant difference (P>.05). However, PEMA-based resin showed a significant decrease (P<.05), which was reflected in a significant increase in residual monomer leaching from PEMA-based resin with the incorporation of 0.5% and 1.0% CDA (P<.05), mainly in the first 48 hours. PMMA-based resin showed no change in monomer leaching (P>.05). For both resins, the CDA release kinetics were related to monomer leaching; for PEMA-based resin, the values were significantly higher in the first 48 hours (P<.05), and for PMMA-based resin, the values were more sustained up to the last day of analysis. ConclusionsThe incorporation of CDA did not affect the physicochemical properties of soft resins. The properties of PMMA were better than those of PEMA.

Multifunctional, Low Friction, Antimicrobial Approach for Biomaterial Surface Enhancement.

Poly(vinyl chloride) (PVC) biomaterials perform a host of life-saving and life-enhancing roles when employed as medical devices within the body. High frictional forces between the device surface and interfacing tissue can, however, lead to a host of complications including tissue damage, inflammation, pain, and infection. We herein describe a versatile surface modification method using multifunctional hydrogel formulations to increase lubricity and prevent common device-related complications. In a clinically relevant model of the urinary tract, simulating the mechanical and biological environments encountered in vivo, coated candidate catheter surfaces demonstrated significantly lower frictional resistance than uncoated PVC, with reductions in coefficient of friction values of more than 300-fold due to hydration of the surface-localized polymer network. Furthermore, this significant lubrication capacity was retained following hydration periods of up to 28 days in artificial urine at pH 6 and pH 9, representing the pH of physiologically normal and infected urine, respectively, and during 200 repeated cycles of applied frictional force. Importantly, the modified surfaces also displayed excellent antibacterial activity, which could be facilely tuned to achieve reductions of 99.8% in adherence of common hospital-acquired pathogens, Staphylococcus aureus and Proteus mirabilis, relative to their uncoated counterparts through incorporation of chlorhexidine in the coating matrix as a model antiseptic. The remarkable, and pH-independent, tribological performance of these lubricious, antibacterial, and highly durable surfaces offers exciting promise for use of this PVC functionalization approach in facilitating smooth and atraumatic insertion and removal of a wide range of medical implants, ultimately maintaining user health and dignity.

Incorporation of chlorhexidine and nano-sized sodium trimetaphosphate into a glass-ionomer cement: Effect on mechanical and microbiological properties and inhibition of enamel demineralization

ObjectiveTo evaluate the antimicrobial/antibiofilm and mechanical properties, and the effect on enamel demineralization of a resin-modified GIC (RMGIC) containing CHX and nano-sized sodium trimetaphosphate (TMP). MethodsRMGIC was associated with CHX (1.25 or 2.5%) and/or TMP (7 or 14%). Antimicrobial and antibiofilm activity were assessed using agar diffusion test and evaluation of biofilm metabolism, respectively. In addition, fluoride (F) and TMP releases as well as the diametral tensile (DTS) and compressive (CS) strength were determined. The percentage of mineral loss (%SH), integrated loss of subsurface hardness (ΔKHN) and enamel F concentrations were also evaluated. ResultsRMGICs containing CHX associated or not with TMP presented higher inhibition zones and effect on S. mutans biofilm. A reduction on CS was observed only for RMGIC + 2.5%CHX and on DTS for RMGIC + 2.5%CHX + 14%TMP. The highest F and TMP releases and lowest %SH and ΔKHN values were detected for RMGIC + 1.25%CHX + 14%TMP and RMGIC + 2.5%CHX + 14%TMP. Higher enamel F concentrations were observed for TMP groups. Conclusion1.25%CHX and 14%TMP increased antimicrobial/antibiofilm action and the ability to prevent enamel demineralization, with minimal effect on the mechanical properties of RMGIC. Clinical significanceRMGIC containing CHX and TMP is an alternative material for patients at high risk for dental caries and can be indicated for low-stress regions or provisional restorations.

Sutures modified by incorporation of chlorhexidine and cinnamaldehyde: anti-Candida effect, bioavailability and mechanical properties

Abstract Introduction Antimicrobial sutures are a therapeutic alternative for the control of oral infections. Objective Incorporate Chlorhexidine (CHX) and Cinnamaldehyde (CN) in sutures and evaluate the anti-Candida effect, release of antimicrobials and mechanical properties. Material and method Silk (S) and Polyglactin 910 (P) sutures were aseptically sectioned (20 mm) and immersed for incorporation in 0.12% CHX, 0.4% CN and 0.9% saline solutions under stirring for 60 minutes (n = 10 / group). Suspensions of 500 μL of Candida albicans (ATCC 90028/ 1 × 106 CFU/mL) were used to evaluate fungal adhesion after the 48 h period at 37°C. The release of CLX and CN were evaluated at 0, 24 and 48 hours (n=3/group) by UV-VIS spectrophotometer (275 nm). The tensile strength and displacement (n=5/group) were evaluated after incorporation (30 mm/min, 50N). Data were analyzed by Anova and Tukey (α = 5%). Result No anti-Candida effect was observed on S and P sutures incorporated with CLX and CN (p&gt;0.05). However, progressive release was verified up to 48 after treatment with CLX (S = 0.075 / P = 0.073 μg/mL) and CN (S = 35.33 /P= 5.72 μg/mL). There was a decrease in tensile strength in S (CLX = 9.9 / CN = 9.9 N) and P (CLX = 14.4 / CN = 15.5 N) (p&lt;0.05). No differences were observed for the displacement for S (CLX = 19.3 / CN=20.7 mm) and P (CLX = 16.2 / CN=15.8 mm) (p&gt;0.05). Conclusion The incorporation of CLX and CN did not have a positive effect on the biological and mechanical properties of the sutures evaluated.

The antibacterial activity of certain disinfectant solutions incorporated into stone mixture

Cross infection control is a way of life and it was realized that a radical changes inthe way of work in the dental clinic and laboratories would detect considerable revisesof traditional working patterns. Disinfection of dental stone cast by incorporation ofChlorhexidine gluconate CHX, Sodium hypochlorite and Madacide 11 separately in aconcentration of (0.5 , 0.5 , full strength) respectively according to the manufacturerinstructions and testing their activity against S.aureus,  -haemolytic streptococcuspneumonia, pseudomonas aeruginosa and E. coli was performed. 5 trials were donefor each disinfectant solution and control (distilled water).The result showed that all the disinfectant solutions showed significant reductionof microbial growth in comparison with the control. Sodium hypochlorite sterilizedental stone cast followed by CHX.Sodium hypochlorite gave negative result for allthe tested microorganisms in all the trials followed by chlorhoxidine gluconatesolutions .Disinfection of stone cast is among recommended methods in infectioncontrol.Sodium hypochlorite was the best among the tested disinfected solutions.

Tunable Drug Loading and Reinforcement of Polycaprolactone Films by Means of Electrospun Nanofibers of Glycolide Segmented Copolymers

AbstractElectrospinning of a segmented copolymer having polyglycolide hard segments is successfully performed from 1,1,1,3,3,3‐hexafluoroisopropanol solutions. During the process, a bactericidal agent, i.e., chlorhexidine (CHX), is effectively loaded, which results in nanofibers with a smaller diameter because of the change in solution conductivity. New fabrics based on molding of alternate layers of poly(ε‐caprolactone) (PCL) films and the electrospun scaffolds of the segmented copolymer are prepared and characterized. The thermal molding process renders a PCL matrix homogeneously reinforced with nanofibers that compensate for the loss of mechanical properties caused by incorporation of CHX. Release of CHX is evaluated in different media. Results vary depending on the layer where the drug is incorporated. Thus, systems with an immediate bacteriostatic effect, as well as systems with a potential long term antimicrobial effect, are obtained. Growth inhibition and adhesion assays demonstrate the fast bactericidal effect of samples with CHX loaded in its outer layers.

Clorexidina incorporada na prótese como estratégia de tratamento para estomatite protética

Objetivo: realizar uma revisão da literatura sobre o tratamento da estomatite protética (AD), a fim de propor a incorporação da clorexidina na prótese como estratégia de tratamento para a SD. Material e Métodos: foi realizada uma busca avançada na base de dados MEDLINE / PubMed, no período de 1976 a 2016. Foram recuperados 65 artigos, utilizando as seguintes palavras-chave: clorexidina, estomatite protética, reembasamento de prótese. Desses, 35 artigos estavam diretamente relacionados ao assunto e, portanto, selecionados para uma revisão narrativa. Resultados: A SD é uma reação inflamatória de etiologia multifatorial, geralmente associada à Candida albicans e frequentemente observada em usuários de próteses totais. A maioria dos tratamentos depende da cooperação do paciente. A clorexidina (CHX) tem atividade antifúngica e pode ser incorporada em materiais de revestimento de prótese sem causar alterações significativas na estrutura da resina dentária e sem depender da adesão do paciente. Conclusão: de acordo com os resultados de estudos in vitro, a CHX liberada de materiais de prótese pode ser conveniente para reduzir biofilmes de prótese e tratar DS, mas estudos adicionais in vivo são necessários para recomendar o uso clínico.

Calcium-silicate mesoporous nanoparticles loaded with chlorhexidine for both anti- Enterococcus faecalis and mineralization properties.

BackgroundIn infected periapical tissues, Enterococcus faecalis is one of the most common dominant bacteria. Chlorhexidine has been proved to show strong antibacterial ability against E. faecalis but is ineffective in promoting mineralization for tissues around root apex. Mesoporous calcium-silicate nanoparticles are newly synthesized biomaterials with excellent ability to promote mineralization and carry-release bioactive molecules in a controlled manner. In this study, mesoporous calcium-silicate nanoparticles were functionalized with chlorhexidine and their releasing profile, antibacterial ability, effect on cell proliferation and in vitro mineralization property were evaluated.ResultsThe chlorhexidine was successfully incorporated into mesoporous calcium-silicate nanoparticles by a mixing-coupling method. The new material could release chlorhexidine as well as Ca2+ and SiO3 2− in a sustained manner with an alkaline pH value under different conditions. The antimicrobial ability against planktonic E. faecalis was dramatically improved after chlorhexidine incorporation. The nanoparticles with chlorhexidine showed no negative effect on cell proliferation with low concentrations. On dentin slices, the new synthesized material demonstrated a similar inhibitory effect on E. faecalis as the chlorhexidine. After being immersed in SBF for 9 days, numerous apatite crystals could be observed on surfaces of the material tablets.ConclusionsMesoporous calcium-silicate nanoparticles loaded with chlorhexidine exhibited release of ions and chlorhexidine, low cytotoxicity, excellent antibacterial ability and in vitro mineralization. This material could be developed into a new effective intra-canal medication in dentistry or a new bone defect filling material for infected bone defects.

Chlorhexidine Nanocapsule Drug Delivery Approach to the Resin-Dentin Interface

In this study, we are introducing a new drug-delivery approach to demineralized dentin substrates through microsized dentinal tubules in the form of drug-loaded nanocapsules. Chlorhexidine (CHX) is widely used in adhesive dentistry due to its nonspecific matrix metalloproteinase inhibitory effect and antibacterial activities. Poly(ε-caprolactone) nanocapsules (nano-PCL) loaded with CHX were fabricated by interfacial polymer deposition at PCL/CHX ratios of 125:10, 125:25, and 125:50. Unloaded nanocapsules (blank) were fabricated as control. The fabricated nanocapsules were characterized in vitro in terms of particle size, surface charges, particle recovery, encapsulation efficiency, and drug loading. Nanocapsule morphology, drug inclusion, structural properties, and crystallinity were investigated by scanning and transmission electron microscopes (SEM/TEM), energy-dispersive x-ray analysis, Fourier transform infrared spectroscopy, and x-ray diffraction. Initial screening of the antibacterial activities and the cytotoxicity of the nanocapsules were also conducted. Nanocapsules, as carried on ethanol/water solution, were delivered to demineralized dentin specimens connected to an ex vivo model setup simulating the pulpal pressure to study their infiltration, penetration depth, and retention inside the dentinal tubules by SEM/TEM. Nanocapsules were Ag labeled and delivered to demineralized dentin, followed by the application of a 2-step etch-and-rinse dentin adhesive. CHX-release profiles were characterized in vitro and ex vivo up to 25 d. Spherical nanocapsules were fabricated with a CHX core coated with a thin PCL shell. The blank nanocapsules exhibited the largest z-average diameter with negatively charged ζ-potential. With CHX incorporation, the nanocapsule size was decreased with a positive shift in ζ-potential. Nano-PCL/CHX at 125:50 showed the highest drug loading, antibacterial effect, and CHX release both in vitro and ex vivo. SEM and TEM revealed the deep penetration and retention of the CHX-loaded nanocapsules inside dentinal tubules and their ability to be gradually degraded to release CHX in vitro and ex vivo. Ag-labeled nanocapsules revealed the close association and even distribution of nanocapsules throughout the resin tag structure. This study demonstrated the potential of introducing this novel drug-delivery approach to demineralized dentin substrates and the resin-dentin interface with nanosized CHX-loaded nanocapsules through the microsized dentinal tubules.

An acrylic reline resin loaded with chlorhexidine: Insights on drug release

ObjectivesDental-biomaterials loaded with drugs are a promising strategy for local infection treatment. In this context, some studies suggest the incorporation of chlorhexidine (CHX), as an antifungal drug, in acrylic reline resins for the treatment of Candida albicans associated dental infections. The purpose of this study was to evaluate the release of CHX from one acrylic reline resin, Kooliner (K). Furthermore, the effect of different media conditions and the drug loading on the CHX release was assessed. MethodsResin specimens were prepared from a hard denture reline material based on poly(ethylmethacrylate) (PEMA) and isobutylmethacrylate (IBMA) containing 2.5, 5.0, 7.5 and 10wt% of CHX. The CHX-loaded resins were incubated in water and artificial saliva (at pH 7) for up to 28 days at 37°C. Chlorhexidine content was determined by UV-spectroscopy (255nm). ResultsCHX release was influenced by media composition and drug loading. CHX demonstrated a similar release profile in the two media, however the water showed the higher amount of release in comparison with the inorganic mimetic saliva. CHX release increased proportionally to the concentration of the CHX added, in a linear trend line. Moreover, a high percentage of CHX was not release up to 28 days. ConclusionsDespite the limitations of the present investigation, results from the present study highlight the need of evaluating drug release not only in water but also in saliva. Strategies that increase the complete release of drug from the material should be investigated in order to prevent the development of multiresistant strains.