Electrospun Tamarindus indica-loaded antimicrobial PMMA/cellulose acetate/PEO nanofibrous scaffolds for accelerated wound healing: In-vitro and in-vivo assessments.

In this work, Tamarindus indica (T. indica)-loaded crosslinked poly(methyl methacrylate) (PMMA)/cellulose acetate (CA)/poly(ethylene oxide) (PEO) electrospun nanofibers were designed and fabricated for wound healing applications. T. indica is a plant extract that possesses antidiabetic, antimicrobial, antioxidant, antimalarial and wound healing properties. T. indica leaves extract of different concentrations were blended with a tuned composition of a matrix comprised of PMMA (10 %), CA (2 %) and PEO (1.5 %), and were electrospun to form smooth, dense and continuous nanofibers as illustrated by SEM investigation. In vitro evaluation of T. indica-loaded nanofibers on normal human skin fibroblasts (HBF4) revealed a high compatibility and low cytotoxicity. T. indica-loaded nanofibers significantly increased the healing activity of scratched HBF4 cells, as compared to the free plant extract, and the healing activity was significantly enhanced upon increasing the plant extract concentration. Moreover, T. indica-loaded nanofibers demonstrated significant antimicrobial activity in vitro against the tested microbes. In vivo, nanofibers resulted in a superior wound healing efficiency compared to the control untreated animals. Hence, engineered nanofibers loaded with potent phytochemicals could be exploited as an effective biocompatible and eco-friendly antimicrobial biomaterials and wound healing composites.

Evaluation of Physical Properties of Denture Base Resins Containing Silver Nanoparticles of Aloe barbadensis Miller, Morinda citrifolia, and Boesenbergia rotunda and Its Anti-microbial Effect: An In Vitro Study.

Introduction The denture bases fabricated from polymethylmethacrylate (PMMA) have some disadvantages, such as surface prone to microbial growth and biofilm accumulation, which contributes to the onset and dissemination of infections among denture wearers. Therefore, the purpose of this in vitro study was to evaluate the flexural strength, hardness, and antimicrobial effect of denture base resin incorporated with 0.05% and 0.1% silver nanoparticles (AgNPs) of Aloe barbadensis miller (aloe vera), Morinda citrifolia (noni), and Boesenbergia rotunda (finger root). Materials and methods A total of 84 PMMA samples were used and were divided into three groups. Flexural strength tests were performed on Group 1 PMMA blocks. Group 2 involved hardness testing of PMMA blocks, whereas Group 3 involved antimicrobial activity. Each group was subsequently split into seven subgroups with differing concentrations of AgNPs: Sub Group 1: control (no AgNPs), Sub Group 2: 0.05% aloe vera AgNPs, Sub Group 3: 0.1% aloe vera AgNPs, Sub Group 4: 0.05% noni AgNPs, Sub Group 5: 0.1% of noni AgNPs, Sub Group 6: 0.05% finger root AgNPs, and Sub Group 7: 0.1% finger root AgNPs. The flexural strength was evaluated using a universal testing machine (Instron 8801). Surface hardness was measured using a Vickers tester (Tukon 1102). For the antimicrobial activity analysis, the samples were incubated in a suitable culture broth containing Candida albicans for 24 hours. Microbial colony count (colony-forming unit (CFU)/mL) was estimated to evaluate the microbial adhesion to the surface of the denture base materials. Statistical analysis The flexural strength, hardness, and CFU between the groups were analyzed using one-way analysis of variance (ANOVA) followed by multiple comparisons with Tukey's honest significant difference (HSD) test (α=0.05). The level of statistical significance was determined at p<0.05. Results It was observed that the mean flexural strength was maximum in PMMA incorporated with 0.05% of aloe vera AgNPs and least in PMMA incorporated with 0.1% noni AgNPs. It was seen that a steady loss in flexural strength is observed from 0.05% to 0.1%. The mean hardness was maximum in PMMA incorporated with 0.1% of noni AgNPs and least in PMMA incorporated with 0.05% aloe vera AgNPs. It was also found that the hardness was directly proportional to the number of nanoparticles. With an increase in the weight percentage of nanoparticles, a steady increase in hardness was seen in all the test groups. In our study, the results showed that finger root 0.1% showed the least CFU with a significant reduction of C. albicans adherence; therefore, it indicates higher anti-fungal activity. Aloe vera 0.05% showed the lowest inhibition of C. albicans, suggesting the least anti-fungal activity. Conclusion Within the limitations of this study, It can thus be concluded that the addition of AgNPs incorporated with plant extracts of Aloe barbadensis miller (aloe vera), Morinda citrifolia (noni), and Boesenbergia rotunda (finger root) can alter the flexural strength, hardness, and microbial adhesion of PMMA. In our study, it can be concluded that flexural strength increases with the addition of AgNPs of 0.5% concentration after which a steady loss is seen. However, the hardness and antimicrobial activity increased with an increase in the concentration of AgNPs in all three plant extracts.

A Polymer-Based Indicator for Detecting Dexamethasone in Herbal Medicine Using Polymethylmethacrylate (PMMA).

Dexamethasone is a chemical drug that is usually added to herbal medicine because of its effects on pain relief, arthritis, anti-inflammation, etc. Chemical drugs should not be used in herbal medicine because uncontrolled consumption causes some side effects. A polymer-based indicator was developed to detect dexamethasone in herbal medicine samples in a fast and simple way compared to instrumental analysis. The indicator strips were made by mixing polymethylmethacrylate (PMMA) polymer with sulfuric acid (H2SO4) as a reagent. When reacting with dexamethasone, H2SO4 can cause the color to change into a specific light pink-purple color. Indicator strips were prepared with a composition of 5% PMMA in ethyl acetate:H2SO4 (9:1) by using the reagent blending method. The indicator strips showed a pink-purple color when they were applied to a positive herb containing dexamethasone. The indicator strips could selectively detect dexamethasone rather than other active substances that are often found in herbal medicine. These indicator strips could also detect dexamethasone with the smallest detection limit of 13.13 ppm, and they had a stability of up to 36 days. Detection was carried out in real samples to show the performance of the indicator strips. The result showed that of nine samples, five were confirmed to contain dexamethasone. These results showed a good agreement with the results of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). According to the result, these indicator strips provide a simple and applicable method for on-site analysis to detect dexamethasone in samples.

Periodic Arrays of Dopants in Silicon by Ultralow Energy Implantation of Phosphorus Ions through a Block Copolymer Thin Film.

In this work, block copolymer lithography and ultralow energy ion implantation are combined to obtain nanovolumes with high concentrations of phosphorus atoms periodically disposed over a macroscopic area in a p-type silicon substrate. The high dose of implanted dopants grants a local amorphization of the silicon substrate. In this condition, phosphorus is activated by solid phase epitaxial regrowth (SPER) of the implanted region with a relatively low temperature thermal treatment preventing diffusion of phosphorus atoms and preserving their spatial localization. Surface morphology of the sample (AFM, SEM), crystallinity of the silicon substrate (UV Raman), and position of the phosphorus atoms (STEM- EDX, ToF-SIMS) are monitored during the process. Electrostatic potential (KPFM) and the conductivity (C-AFM) maps of the sample surface upon dopant activation are compatible with simulated I-V characteristics, suggesting the presence of an array of not ideal but working p-n nanojunctions. The proposed approach paves the way for further investigations on the possibility to modulate the dopant distribution within a silicon substrate at the nanoscale by changing the characteristic dimension of the self-assembled BCP film.

Comparison of the color stability and surface roughness of 3-unit provisional fixed partial dentures fabricated by milling, conventional and different 3D printing fabrication techniques.

OBJECTIVES: To compare the color stability and surface roughness of 3-unit provisional fixed partial dentures (FPDs) fabricated by milling, conventional, and different 3D printing fabrication techniques. METHODS: A total sample of 160, 3-unit FPDs were subdivided into four groups; subtractive milled resin (SM), two 3D printed resins (Stereolithography; SLA and Digital Light Processing; DLP) and conventional self-cured polymethyl methacrylate resin (CM). Surface roughness (Ra) was assessed twice; at baseline (Ra1) and after artificial tooth brushing (Ra2). Color of the samples was measured after immersion in four different solutions (cola, coffee, black tea and distilled water) at three time intervals (1, 7 and 30 days). Comparisons of the Ra and the color change (∆E00) were done using one-way ANOVA followed by multiple pairwise comparisons using Bonferroni adjusted significance level. Comparisons of the Ra at two stages (Ra1 and Ra2) were done using paired t-test. Univariate linear regression was performed followed by multivariable regression to assess the association between ∆E00 and different factors (materials, solution, and time). Significance was set at P value <0.05. RESULTS: The highest change in Ra following artificial tooth brushing was reported in the CM group, while the lowest change was reported in the SM group, with a significant difference between both groups (P<0.001). SM group had significantly lower ∆E00 than the CM group followed by 3D printed SLA and DLP groups (P<0.001). Storage in coffee for 30 days showed the highest ∆E00 values (P<0.001). CONCLUSIONS: SM resin showed the least surface roughness and color change followed by 3D printed SLA resin. The difference in printing technology affected the tested properties with improved readings of 3D printed SLA resin. CLINICAL SIGNIFICANCE: Milled provisional FPDs showed higher surface smoothness and color stability than those fabricated by SLA printing technology, but with no significant difference between both groups. Therefore, SLA printed resins can be an adequate substitute to milled resins in the fabrication of provisional FPDs to overcome the high expenses of milled provisional FPDs.

N-Acetyl Cysteine-Mediated Improvements in Dental Restorative Material Biocompatibility.

The fibroblast-rich gingival tissue is usually in contact with or adjacent to cytotoxic polymer-based dental restoration materials. The objective of this study was to determine whether the antioxidant amino acid, N-acetyl cysteine (NAC), reduces the toxicity of dental restorative materials. Human oral fibroblasts were cultured with bis-acrylic, flowable composite, bulk-fill composite, self-curing acrylic, and titanium alloy test specimens. Cellular behavior and function were analyzed on and around the materials. Impregnation of the bulk-fill composite and self-curing acrylic with NAC reduced their toxicity, improving the attachment, growth, and function of human oral fibroblasts on and around the materials. These mitigating effects were NAC dose dependent. However, NAC impregnation of the bis-acrylic and flowable composite was ineffective, with no cells attaching to nor around the materials. Although supplementing the culture medium with NAC also effectively improved fibroblast behaviors, direct impregnation of materials with NAC was more effective than supplementing the cultures. NAC-mediated improvements in fibroblast behavior were associated with reduced production of reactive oxygen species and oxidized glutathione together with increased glutathione reserves, indicating that NAC effectively directly scavenged ROS from materials and reinforced the cellular antioxidant defense system. These results establish a proof of concept of NAC-mediated improvements in biocompatibility in the selected dental restorative materials.

In vitro evaluation of bone cements impregnated with selenium nanoparticles stabilized by phosphatidylcholine (PC) for application in bone.

One of the most common prophylactic techniques to solve prosthetic joint infection (PJI) is incorporation of antibiotics into acrylic bone cement to prevent bacterial colonization and proliferation by providing local antibiotic delivery directly at the implant site. Further, there has been a significant concern over the efficacy of commonly used antibiotics within bone cement due to the rise in multi-drug resistant (MDR) microorganisms. Selenium is an essential trace element that has multiple beneficial effects for human health and its chemotherapeutic action is well known. It was reported that nanostructured selenium enhanced bone cell adhesion and has an increased osteoblast function. In this context, we used the selenium nanoparticles (SeNPs) to improve antibacterial and antioxidant properties of poly (methyl methacrylate) (PMMA) and tri calcium phosphate (TCP)-based bone cements, and to reduce of the infection risk caused by orthopedic implants. As another novelty of this study, we proposed phosphatidylcholine (PC) as a unique and natural stabilizer in the synthesis of selenium nanoparticles. After the structural analysis of the prepared bone cements was performed, in vitro osteointegration and antibacterial efficiency were tested using MC3T-E1 (mouse osteoblastic cell line) and SaOS-2 (human primary osteogenic sarcoma) cell lines, and S. aureus (Gram positive) and E.coli (Gram negative) strains, respectively. More importantly, PC-SeNPs-reinforced bone cements exhibited significant effect against E. coli, compared to S. aureus and a dose-dependent antibacterial activity against both bacterial strains tested. Meanwhile, these bone cements induced the apoptosis of SaOS-2 through increased reactive oxygen species without negatively influencing the viability of the healthy cell line. Furthermore, the obtained confocal images revealed that PC-SeNPs (103.7 ± 0.56 nm) altered the cytoskeletal structure of SaOS-2 owing to SeNPs-induced apoptosis, when MC3T3-E1 cells showed a typical spindle-shaped morphology. Taken together, these results highlighted the potential of PC-SeNPs-doped bone cements as an effective graft material in bone applications.

Novel indicators to better monitor the collection and recovery of (critical) raw materials in WEEE: Focus on screens.

Currently, in the European Union (EU), e-waste chain performance is assessed by technical indicators that aim to ensure system compliance with collection and recovery targets set by the WEEE Directive. This study proposes indicators to improve WEEE flow monitoring beyond the current overall weight-based approach, including complementary flows and treatment performance. A case study focused on the screen category in France is presented. In 2017, the collection rate of cathode-ray tube screens (CRT) was 68%, while for flat panel display (FPD) generated only 14% was collected. CRT screens have less precious and critical materials than FDP. Thus, elements like cobalt and gold highly concentrated in FPD, have a collection rate two to four times lower than elements such as copper (37%) which represents a high proportion in CRTs. Recycling is the main treatment in France. Nevertheless, the recycling rate per element varies significantly due to the low collection, and also the lack of technology and/or secondary raw materials market. The elements with higher recycling rates are base metals such as copper (28%), followed by precious metals like silver (23%), and gold (13%). Except for palladium, the recycling rate of the critical raw materials targeted in the study ranged from 6% (cobalt) to 0% (e.g. neodymium and indium). The results stress the need for indicators to support the development of WEEE chain from waste management to secondary (critical) raw materials suppliers.

Multifunctional bone cement for synergistic magnetic hyperthermia ablation and chemotherapy of osteosarcoma.

Myelosuppression, gastrointestinal toxicity and hypersensitivities always accompany chemotherapy of osteosarcoma (OS). In addition, the intricate karyotype of OS, the lack of targeted antitumor drugs and the bone microenvironment that provides a protective alcove for tumor cells reduce the therapeutic efficacy of chemotherapy. Here, we developed a multifunctional bone cement loaded with Fe3O4 nanoparticles and the antitumor drug doxorubicin (DOX/Fe3O4@PMMA) for synergistic MH ablation and chemotherapy of OS. The localized intratumorally administered DOX/Fe3O4@PMMA can change from liquid into solid at the tumor site via a polyreaction. The designed multifunctional bone cement was constructed with Fe3O4 nanoparticles, PMMA, and an antitumor drug approved by the U.S. Food and Drug administration (FDA). The injectability, magnetic hyperthermia (MH) performance, controlled drug release profile, and synergistic therapeutic effect of DOX/Fe3O4@PMMA in vitro were investigated in detail. Furthermore, the designed DOX/Fe3O4@PMMA controlled the release of DOX, enhanced the apoptosis of OS tissue, and inhibited the proliferation of tumor cells, demonstrating synergistic MH ablation and chemotherapy of OS in vivo. The biosafety of DOX/Fe3O4@PMMA was also evaluated in detail. This strategy significantly reduced surgical time, avoided operative wounds and prevented patient pain, showing a great clinical translational potential for OS treatment.

PMMA-Fe3O4 for internal mechanical support and magnetic thermal ablation of bone tumors.

Background: Minimally invasive modalities are of great interest in the field of treating bone tumors. However, providing reliable mechanical support and fast killing of tumor cells to achieve rapid recovery of physical function is still challenging in clinical works. Methods: A material with two functions, mechanical support and magnetic thermal ablation, was developed from Fe3O4 nanoparticles (NPs) distributed in a polymethylmethacrylate (PMMA) bone cement. The mechanical properties and efficiency of magnetic field-induced thermal ablation were systematically and successfully evaluated in vitro and ex vivo. CT images and pathological examination were successfully applied to evaluate therapeutic efficacy with a rabbit bone tumor model. Biosafety evaluation was performed with a rabbit in vivo, and a cytotoxicity test was performed in vitro. Results: An NP content of 6% Fe3O4 (PMMA-6% Fe3O4, mFe: 0.01 g) gave the most suitable performance for in vivo study. At the 56-day follow-up after treatment, bone tumors were ablated without obvious side effects. The pathological examination and new bone formation in CT images clearly illustrate that the bone tumors were completely eliminated. Correspondingly, after treatment, the tendency of bone tumors toward metastasis significantly decreased. Moreover, with well-designed mechanical properties, PMMA-6%Fe3O4 implantation endowed tumor-bearing rabbit legs with excellent bio-mimic bone structure and internal support. Biosafety evaluation did not induce an increase or decrease in the immune response, and major functional parameters were all at normal levels. Conclusion: We have presented a novel, highly efficient and minimally invasive approach for complete bone tumor regression and bone defect repair by magnetic thermal ablation based on PMMA containing Fe3O4 NPs; this approach shows excellent heating ability for rabbit VX2 tibial plateau tumor ablation upon exposure to an alternating magnetic field (AMF) and provides mechanical support for bone repair. The new and powerful dual-function implant is a promising minimally invasive agent for the treatment of bone tumors and has good clinical translation potential.

Addition of ceftaroline fosamil or vancomycin to PMMA: An in vitro comparison of biomechanical properties and anti-MRSA efficacy.

BACKGROUND: Ceftaroline is a cephalosporin that is effective against methicillin-resistant Staphylococcus aureus (MRSA) infections. The objective of this study was to determine the feasibility of using ceftaroline-loaded Polymethyl methacrylate (PMMA) as antibiotic cement against MRSA versus vancomycin-loaded PMMA in an in vitro setting. METHODS: PMMA pellets were prepared with three separate concentrations of each of the two antibiotics tested. They were tested to determine the effect of increasing concentration of antibiotics on the biomechanical properties of PMMA and antibiotic activity by measuring the zone of inhibition and broth elution assay. RESULTS: Ceftaroline PMMA at 3 wt%, three-point bending was 37.17 ± 0.51 N ( p < 0.001) and axial loading was 41.95 N ± 0.51 ( p < 0.001). At 5-wt% vancomycin-PMMA, three-point bending was 41.65 ± 0.79 N ( p = 0.02) and axial loading was 49.49 ± 2.21 N ( p = 0.01). Stiffness of ceftroline-loaded PMMA in low and medium concentration was significantly higher than the vancomycin. The zone of inhibition for ceftaroline was higher than vancomycin. Ceftaroline at 3 wt% eluted up to 6 weeks (0.3 ± 0.1 µg/ml) above the minimum inhibitory concentration (MIC) and vancomycin at 2.5 wt% eluted up to 3 weeks, same as MIC, that is, 0.5 ± 0.0 µg/ml. CONCLUSIONS: Ceftaroline, loaded at similar concentrations as vancomycin into PMMA, is a more potent alternative based on its more favourable bioactivity and elution properties, while having a lesser effect on the mechanical properties of the cement. The use of 3-wt% ceftaroline as antibiotic laden PMMA against MRSA is recommended. It should be noted that this was an in vitro study and to determine the clinical efficacy would need prospective, controlled and randomized studies.

Calcium Phosphate Spacers for the Local Delivery of Sitafloxacin and Rifampin to Treat Orthopedic Infections: Efficacy and Proof of Concept in a Mouse Model of Single-Stage Revision of Device-Associated Osteomyelitis.

Osteomyelitis is a chronic bone infection that is often treated with adjuvant antibiotic-impregnated poly(methyl methacrylate) (PMMA) cement spacers in multi-staged revisions. However, failure rates remain substantial due to recurrence of infection, which is attributed to the poor performance of the PMMA cement as a drug release device. Hence, the objective of this study was to design and evaluate a bioresorbable calcium phosphate scaffold (CaPS) for sustained antimicrobial drug release and investigate its efficacy in a murine model of femoral implant-associated osteomyelitis. Incorporating rifampin and sitafloxacin, which are effective against bacterial phenotypes responsible for bacterial persistence, into 3D-printed CaPS coated with poly(lactic co-glycolic) acid, achieved controlled release for up to two weeks. Implantation into the murine infection model resulted in decreased bacterial colonization rates at 3- and 10-weeks post-revision for the 3D printed CaPS in comparison to gentamicin-laden PMMA. Furthermore, a significant increase in bone formation was observed for 3D printed CaPS incorporated with rifampin at 3 and 10 weeks. The results of this study demonstrate that osteoconductive 3D printed CaPS incorporated with antimicrobials demonstrate more efficacious bacterial colonization outcomes and bone growth in a single-stage revision in comparison to gentamicin-laden PMMA requiring a two-stage revision.

Effects of alumina nanoparticles on the microstructure, strength and wear resistance of poly(methyl methacrylate)-based nanocomposites prepared by friction stir processing.

In this study, alumina-reinforced poly(methyl methacrylate) nanocomposites (PMMA/Al2O3) containing up to 20vol% nanoparticles with an average diameter of 50nm were prepared by friction stir processing. The effects of nanoparticle volume fraction on the microstructural features and mechanical properties of PMMA were studied. It is shown that by using a frustum pin tool and employing an appropriate processing condition, i.e. a rotational speed of 1600rpm/min and transverse velocity of 120mm/min, defect free nanocomposites at microscale with fine distribution of the nanoparticles can successfully been prepared. Mechanical evaluations including tensile, flexural, hardness and impact tests indicate that the strength and toughness of the material gradually increases with the nanoparticle concentration and reach to a flexural strength of 129MPa, hardness of 101 Shore D, and impact energy 2kJ/m2 for the nanocomposite containing 20vol% alumina. These values are about 10% and 20% better than untreated and FSP-treated PMMA (without alumina addition). Fractographic studies indicate typical brittle features with crack deflection around the nanoparticles. More interestingly, the sliding wear rate in a pin-on-disk configuration and the friction coefficient are reduced up to 50% by addition of alumina nanoparticles. The worn surfaces exhibit typical sliding and ploughing features.

Encapsulation of Piper cabralanum (Piperaceae) nonpolar extract in poly(methyl methacrylate) by miniemulsion and evaluation of increase in the effectiveness of antileukemic activity in K562 cells.

This study aimed to synthesize and characterize nanoparticles (NPs) of poly(methyl methacrylate) (PMMA) and evaluate their ability to incorporate plant extracts with antitumor activity and low dissolution in aqueous media. The extract used was n-hexane partition of the methanol extract of Piper cabralanum (PCA-HEX). PMMA NPs were obtained using the mini-emulsion method, which was able to encapsulate almost 100% of PCA-HEX. The synthesized polymeric particles presented with a size of 200 nm and a negative charge. Cytotoxicity tests by MTT and trypan blue assays showed that NPs without PCA-HEX did not kill leukemic cells (K562 cells). NPs containing PCA-HEX were able to enhance cell death when compared to pure extract. The results showed that PMMA NPs could be useful as a drug delivery system as they can enhance the antitumor activity of the PCA-HEX extract by more than 20-fold. PMMA NPs containing plant extracts with antitumor activities may be an alternative to control the evolution of diseases such as leukemia.

Zinc Ion Removal on Hybrid Pectin-Based Beads Containing Modified Poly(Methyl Methacrylate) Waste.

A new hybrid sorbent in the form of round beads containing modified poly(methyl methacrylate) (PMMA) waste immobilized in pectin and crosslinked with calcium ions was prepared. A previously obtained and characterized powdered poly(methyl methacrylate)-based sorbent was used. Batch and column studies on the new material's sorption-desorption properties were performed. Two kinetic models (pseudo-first- and pseudo-second-order) and three isotherms (Langmuir, Langmuir bisite and Freundlich) were used to describe the results. Breakthrough and elution curves were also obtained. Nitric, hydrochloric, and sulfuric acid of various concentrations were used in the desorption studies. Higher sorption affinity of zinc(II) ions to hybrid sorbent than to pectin alone, reflected by higher values of the Langmuir and Freundlich model parameters, was observed. The maximum sorption capacities, calculated based on the best-fitted models, were 50.2 mg/g (Langmuir bisite) and 42.2 mg/g (Langmuir) for hybrid and only pectin beads, respectively. The stripping of Zn ions using 0.1 M solutions of mineral acids was similarly effective in the case of both sorbents. The mass balance calculated for the column studies showed about 100% recovery of zinc in a sorption-desorption cycle. By applying the hybrid sorbent under the studied conditions it is possible to purify Zn in water to the level permitted by law and concentrate Zn(II) ions by about 60 times.

Advances in the local and targeted delivery of anti-infective agents for management of osteomyelitis.

INTRODUCTION: Osteomyelitis, a common and debilitating invasive infection of bone, is a frequent complication following orthopedic surgery and causes pathologic destruction of skeletal tissues. Bone destruction during osteomyelitis results in necrotic tissue, which is poorly penetrated by antibiotics and can serve as a nidus for relapsing infection. Osteomyelitis therefore frequently necessitates surgical debridement procedures, which provide a unique opportunity for targeted delivery of antimicrobial and adjunctive therapies. Areas covered: Following surgical debridement, tissue voids require implanted materials to facilitate the healing process. Antibiotic-loaded, non-biodegradable implants have been the standard of care. However, a new generation of biodegradable, osteoconductive materials are being developed. Additionally, in the face of widespread antimicrobial resistance, alternative therapies to traditional antibiotic regimens are being investigated, including bone targeting compounds, antimicrobial surface modifications of orthopedic implants, and anti-virulence strategies. Expert commentary: Recent advances in biodegradable drug delivery scaffolds make this technology an attractive alternative to traditional techniques for orthopedic infection that require secondary operations for removal. Advances in novel treatment methods are expanding the arsenal of viable antimicrobial treatment strategies in the face of widespread drug resistance. Despite a need for large scale clinical investigations, these strategies offer hope for future treatment of this difficult invasive disease.

Combination therapy with vancomycin-loaded calcium sulfate and vancomycin-loaded PMMA in the treatment of chronic osteomyelitis.

BACKGROUND: Chronic post-traumatic and postoperative osteomyelitis is a refractory disease which results in significant morbidity and mortality. The effect of combination therapy with vancomycin-loaded calcium sulfate and vancomycin-loaded polymethyl methacrylate (PMMA) was unknown. METHODS: Fifty-one patients suffering from chronic post-traumatic or postoperative osteomyelitis of the lower extremities were included in the retrospective investigation. The patients were assigned to the study group of the combination therapy with antibiotic-loaded calcium sulfate and antibiotic-loaded PMMA or the control group of the antibiotic-loaded PMMA. Hematological parameters, eradication of infection, rate of infection recurrence and reoperation rate were evaluated during the follow-up. RESULTS: The cases were followed up for an average of 24 months (range, 15-48 months) after the first-stage surgical operation. In the study group, all the patients revealed complete calcium sulfate resorption at an average of 6 weeks (range, 30-60 days). In the study group, infection was primarily eradicated in 92.31% (24 of 26) of patients and re-operation rate of 7.69% (2 of 26) after the first-stage surgery. Two patients underwent further surgical operation in the study group. One case achieved infection eradication in the recurrent two cases, with a secondary infection eradication rate of 96.15% (25 of 26). There was no persistent infection in the study group. In the control group, infection was eradicated in 64.00% (16 of 25) of patients and re-operation rate was 36.00% (9 of 25) after the first-stage surgery. Nine patients in the control group underwent further surgical operation. Two case achieved infection eradication in these cases who suffered from persistent or recurrent infection, with a secondary infection eradication rate of 72.00% (18 of 25). There was more re-operation rate in the control group (PMMA group, 9 vs combination therapy group, 2; P = 0.034). CONCLUSION: The combination therapy with vancomycin-loaded calcium sulfate and vancomycin-loaded PMMA possibly achieved more effective control of infection in the treatment of osteomyelitis through synergistic effect. The immediate structural stabilization and higher concentration of antibiotic at the local site of infection may be achieved through the combination of biodegradable and non-biodegradable devices in the treatment of chronic post-traumatic and postoperative osteomyelitis. The study was retrospectively registered at 11/16/2016 (TRN: NCT02968693).

Synthetic Fillers for Facial Rejuvenation.

Soft tissue filler procedures have increased dramatically in popularity in the United States. Synthetic fillers such as calcium hydroxyapatite (CaHA), polymethyl methacrylate (PMMA), and poly-l-lactic acid (PLLA), and silicone provide initial volume replacement but have an additional biostimulatory effect to supplement facial volumization. Indications include human immunodeficiency virus lipoatrophy and nasolabial folds for CaHA and PLLA and atrophic acne scars for PMMA. Most clinical use of these synthetic fillers is in an off-label fashion. Beyond the proper choice of a synthetic filler, careful consideration of dilution, injection method, and postprocedural care allows for successful and consistent results.

Orthopedic application of spikenard herbal rhizome decorated microstructured polymer biocomposites and their in vitro cytotoxicity.

The present study explores the synthesis of highly potential polymer biocomposite from Nardostachys jatamansi rhizome extract. The polymer biocomposites were synthesized from methyl methacrylate by free radical polymerization. ATR-IR enunciate the functional groups attributed at 956 cm-1 (aromatic), a peak appeared at 1685 cm-1 (-C[bond, double bond]O), 1186 cm-1 (-O-CH3), 1149 cm-1 (-C-O-C) framework and 1279 cm-1 (-C-O), which are good agreement for the formation composites. The quantitative evaluations of antimicrobial studies were analyzed by serial dilution method and also improved activity in orthopedic infection pathogens. Cytocompatibility was analyzed by keratinocyte cell lines and it may be used for various biomedical applications.

Surgical treatment of the osteoporotic spine with bone cement-injectable cannulated pedicle screw fixation: technical description and preliminary application in 43 patients

OBJECTIVES: To describe a new approach for the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws. METHODS: Between June 2010 and February 2013, 43 patients with degenerative spinal disease and osteoporosis (T-score <-2.5) underwent lumbar fusion using cement-injectable cannulated pedicle screws. Clinical outcomes were evaluated using a Visual Analog Scale and the Oswestry Disability Index. Patients were given radiographic follow-up examinations after 3, 6, and 12 months and once per year thereafter. RESULTS: All patients were followed for a mean of 15.7±5.6 months (range, 6 to 35 months). The Visual Analog Scale and Oswestry Disability Index scores showed a significant reduction in back pain (p = 0.018) and an improvement in lower extremity function (p = 0.025) in patients who underwent lumbar fusion using the novel screw. Intraoperative cement leakage occurred in four patients, but no neurological complications were observed. Radiological observation indicated no loosening or pulling out of the novel screw, and bone fusion was excellent. CONCLUSIONS: The described polymethylmethacrylate augmentation technique using bone cement-injectable cannulated pedicle screws can reduce pain and improve spinal dysfunction in osteoporotic patients undergoing osteoporotic spine surgery. .