Guaiacol/ß-cyclodextrin for rapid healing of dry socket: antibacterial activity, cytotoxicity, and bone repair-an animal study.

PURPOSE: Dry socket (DS) is one the most common and symptomatic post-extraction complications; however, no consensus on its treatment has been reached. This study aimed to develop a novel dressing material for DS containing the phenolic agent guaiacol and evaluate its biological properties. METHODS: An inclusion complex of guaiacol and ß-cyclodextrin (Gu/ßcd) was prepared by freeze-drying. Its antibacterial activity over six oral bacteria was analyzed using the microdilution method, and its cytotoxicity in osteoblasts was assessed with the MTT assay. The alveolar healing process induced by Gu/ßcd was evaluated histologically after the treatment of DS in rats. RESULTS: ßcd complexation potentiated Gu's antibacterial effect and reduced its cytotoxicity in osteoblasts. Bone trabeculae were formed in the alveolar apices of rats treated with Gu/ßcd by day 7. On day 14, woven bone occupied the apical and middle thirds of the sockets; on day 21, the entire alveolus was filled by newly formed bone, which was in a more advanced stage of repair than the positive control (Alvogyl™). CONCLUSION: The improvement in Gu's biological properties in vitro and the rapid alveolar repair in comparison with Alvogyl™ in vivo demonstrated the benefits of the Gu/ßcd complex as a future alternative for the treatment of DS.

PLGA nanofibers improves the antitumoral effect of daunorubicin.

The objective of this study was to evaluate the in vivo anti-inflammatory angiogenesis activity and in vitro cytotoxicity on normal and cancer cell models of a drug delivery system consisting of poly(lactic-co-glycolic acid) nanofibers loaded with daunorubicin (PLGA-DNR) that were fabricated using an electrospinning process. The PLGA-DNR nanofibers were also characterized by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and confocal fluorescence microscopy. In vitro release of DNR from the nanofibers and its corresponding mechanism were also evaluated. Sixty-five percent of the DNR was released in an initial burst over 8h, and by 1224 h, eighty-five percent of the DNR had been released. The Higuchi model yielded the best fit to the DNR release profile over the first 8h, and the corresponding data from 24 to 1224 h could be modeled using zero-order kinetics. The PLGA-DNR nanofibers exhibited a higher cytotoxicity to A431 cells than free DNR but a cytotoxicity similar to free DNR against fibroblast cells. A higher antiangiogenic effect of PLGA nanofibers was observed in the in vivo data when compared to free DNR, and no inflammatory potential was observed for the nanofibers.

Development of a calcium phosphate nanocomposite for fast fluorogenic detection of bacteria.

Current procedures for the detection and identification of bacterial infections are laborious, time-consuming, and require a high workload and well-equipped laboratories. Therefore the work presented herein developed a simple, fast, and low cost method for bacterial detection based on hydroxyapatite nanoparticles with a nutritive mixture and the fluorogenic substrate. Calcium phosphate ceramic nanoparticles were characterized and integrated with a nutritive mixture for the early detection of bacteria by visual as well as fluorescence spectroscopy techniques. The composite was obtained by combining calcium phosphate nanoparticles (Ca:P ratio, 1.33:1) with a nutritive mixture of protein hydrolysates and carbon sources, which promote fast bacterial multiplication, and the fluorogenic substrate 4-methylumbellipheryl-ß-D-glucuronide (MUG). The composite had an average particle size of 173.2 nm and did not show antibacterial activity against Gram-negative or Gram-positive bacteria. After an Escherichia coli suspension was in contact with the composite for 60-90 min, fluorescence detected under UV light or by fluorescence spectrophotometer indicated the presence of bacteria. Intense fluorescence was observed after incubation for a maximum of 90 min. Thus, this calcium phosphate nanocomposite system may be useful as a model for the development of other nanoparticle composites for detection of early bacterial adhesion.

Efficacy of coral-hydroxyapatite and biphasic calcium phosphate for early bacterial detection.

Nano- or microhydroxyapatites with microbiological properties are being used to detect pathogens in clinical samples and industrial environments. In this study, the calcium phosphates coral-hydroxyapatite and biphasic calcium phosphate were characterized physicochemically using x-ray diffraction, thermogravimetric, and differential thermal analysis. The morphology, texture, and chemical composition of the ceramics were also investigated using scanning electron microscopy with energy dispersive spectroscopy. The biocompatibility of the ceramics was evaluated using Escherichia coli and Enterococcus faecalis. Microorganisms were detected by incorporating the enzyme markers 4-metilumbelliferil-ß-d-glucoside and 4-metilumbelliferil-ß-d-glucuronide in the ceramic powders and evaluating fluorescence. The characterization of the ceramics revealed typical characteristics, such as crystallinity, thermal stability, and chemical composition, consistent with other calcium phosphates. The calcium phosphates coral-hydroxyapatite and biphasic calcium phosphate ceramics differed from one another in morphology, structural topography, particle size distribution, and the capacity to absorb water. These properties can influence the rates of microbiological responses and bacterial detection. Although both materials are suitable for use as structural supports in microbial diagnostic systems, BCP was more efficient and detected E. coli and E. faecalis more rapidly than CHA.

Evaluation of antimicrobial activity and cell viability of Aloe vera sponges

Background: Aloe vera L., member of the Liliaceae family, has been shown to stimulate cell proliferation and contribute to healing and angiogenesis, has anti-bacterial, anti-fungal and anti-inflammatory activity. In addition, Aloe vera can be used as a support for drug transport. Our objective is to evaluate antimicrobial activity and cytotoxicity of sponges of Aloe vera L. for use as a carrying support of drugs. Results: In this work, sponge of free Aloe vera (AV) loaded with amoxicillin (AMX) or nystatin (NYS) at 1% w/w, were prepared and physico-chemically characterized via X-ray diffraction, Fourier Transform Infrared Spectroscopy and thermal analysis. Antimicrobial potency of AV sponge alone, loaded with AMX or NYS, against strains of Streptococcus mutans, Staphylococcus aureus, Aggregatibacter actinomycetemcomitans, Enterococcus faecalis and Candida albicans was determined. Osteoblasts and human gingival fibroblasts were cultivated on AV, Aloe vera loaded with amoxicillin (AV/AMX) and Aloe vera loaded with nystatin (AV/NYS) and cellular viability was assessed. The physico-chemical characterization performed suggested that the loaded drugs were dispersed in the sponge and those interactions between the AV sponge and the loaded drugs were weak. Furthermore, AV loaded with AMX or NYS demonstrated antimicrobial potency and osteoblasts and fibroblasts were viable after 24 hrs on free AV, and AV loaded with AMX or NYS. Conclusions: Our results indicate that sponges of free AV, loaded with AMX or NYS, are biocompatible and exhibit antimicrobial activity.

Effect of testosterone incorporation on cell proliferation and differentiation for polymer-bioceramic composites.

In the current study, we characterized the polycaprolactone (PCL), poly(lactic acid-co-glycolic acid) (PLGA), and biphasic calcium phosphate (BCP) composites coated with testosterone propionate (T) using Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). Osteoblastic cells were seeded with PCL/BCP, PCL/BCP/T, PLGA/PCL/BCP and PLGA/PCL/BCP/T scaffolds, and cell viability, proliferation, differentiation and adhesion were analyzed. The results of physic-chemical experiments showed no displacements or suppression of bands in the FTIR spectra of scaffolds. The XRD patterns of the scaffolds showed an amorphous profile. The osteoblastic cells viability and proliferation increased in the presence of composites with testosterone over 72 h, and were significantly greater when PLGA/PCL/BCP/T scaffold was tested against PCL/BCP/T. Furthermore alkaline phosphatase production was significantly greater in the same group. In conclusion, the PLGA/PCL/BCP scaffold with testosterone could be a promising option for bone tissue applications due to its biocompatibility and its stimulatory effect on cell proliferation.