Bordetella pertussis infection in children with severe pneumonia, Philippines, 2012-2015.

A case-comparison study was conducted based on an observational study of severe pneumonia among hospitalized children in the Philippines. The children, from 8days to 13years old and hospitalized with clinical diagnosis of severe or very severe pneumonia from August 2012 to February 2015, were recruited. Nasopharyngeal swabs were collected from 1152 cases and B. pertussis were detected from 34 cases by PCR. Pertussis-positive cases were more likely to have no fever, more than one week of coughing and breathing difficulty, decreased breathing sounds, and central cyanosis than pertussis- negative cases. The percentage of underweight was significantly higher in pertussis-positive cases than pertussis-negative cases. Pertussis-positive cases showed remarkably higher fatality rate than pertussis-negative cases. All of the fatal cases among pertussis-positive cases were less than 6months old. More attention should be given to protect young infants from pertussis.

Bioactive glass incorporation in calcium phosphate cement-based injectable bone substitute for improved in vitro biocompatibility and in vivo bone regeneration.

In this work, we fabricated injectable bone substitutes modified with the addition of bioactive glass powders synthesized via ultrasonic energy-assisted hydrothermal method to the calcium phosphate-based bone cement to improve its biocompatibility. The injectable bone substitutes was initially composed of a powder component (tetracalcium phosphate, dicalcium phosphate dihydrate and calcium sulfate dehydrate) and a liquid component (citric acid, chitosan and hydroxyl-propyl-methyl-cellulose) upon which various concentrations of bioactive glass were added: 0%, 10%, 20% and 30%. Setting time and compressive strength of the injectable bone substitutes were evaluated and observed to improve with the increase of bioactive glass content. Surface morphologies were observed via scanning electron microscope before and after submersion of the samples to simulated body fluid and increase in apatite formation was detected using x-ray diffraction machine. In vitro biocompatibility of the injectable bone substitutes was observed to improve with the addition of bioactive glass as the proliferation/adhesion behavior of cells on the material increased. Human gene markers were successfully expressed using real time-polymerase chain reaction and the samples were found to promote cell viability and be more biocompatible as the concentration of bioactive glass increases. In vivo biocompatibility of the samples containing 0% and 30% bioactive glass were evaluated using Micro-CT and histological staining after 3 months of implantation in male rabbits' femurs. No inflammatory reaction was observed and significant bone formation was promoted by the addition of bioactive glass to the injectable bone substitute system.

Biphasic calcium phosphate loading on polycaprolactone/poly(lacto-co-glycolic acid) membranes for improved tensile strength, in vitro biocompatibility, and in vivo tissue regeneration.

Electrospun polycaprolactone and poly(lacto-co-glycolide) membranes were loaded with biphasic calcium phosphate powder to facilitate osteoconductivity. Different concentrations of biphasic calcium phosphate powder were added to the polymer solution, and successful loading was confirmed by X-ray diffraction analysis, transmission electron microscope, and scanning electron microscope with energy-dispersive spectroscopy visualization. The effect of the added biphasic calcium phosphate on the polymer membrane was investigated in terms of the material's tensile strength and strain, in vitro cytocompatibility, and in vivo tissue regeneration. It was observed that the tensile strength of the membranes increased with the addition of the biphasic calcium phosphate powder. Immersion in simulated body fluid solution for seven days leads to the formation of apatite-like deposits in the fibers, which further improved the mechanical stability. Moreover, proliferation and adhesion of osteoblast-like cells were more apparent upon the addition of the biphasic calcium phosphate powder as seen with the increasing cell density from (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and micrographs from scanning electron microscope and confocal microscopy. Sample membranes were also implanted to investigate the membrane's ability to regenerate bone in a rat calvarium. Histological staining and micro-CT histomorphometric analyses showed neo-bone formation in the implanted rat skull.

Encapsulation of simvastatin in PLGA microspheres loaded into hydrogel loaded BCP porous spongy scaffold as a controlled drug delivery system for bone tissue regeneration.

The main objective of this study was to fabricate a controlled drug delivery which is simultaneously effective for bone regeneration. We have encapsulated simvastatin, which enhances osteoblastic activity, in the poly (lactic-co-glycolic acid) microspheres. Loading of these microspheres inside the spongy scaffold of biphasic calcium phosphate with the help of Gelatin (Gel) hydrogel controls the delivery of the drug, and ensures a more favorable drug release profile. As a result, some significant benefits have been achieved, such as higher mechanical strength, excellent biocompatibility in in vitro experiments. For determining the characteristics of the composite scaffold, several analysis, such as scanning electron microscope, EDX, X-ray diffraction, FT-IR, and porosity were carried out. The in vitro drug release profile clearly indicates that simvastatin release from the microsphere was more controlled and prolonged after loading in the scaffold. Biocompatibility was certainly higher for the final composite scaffold compared to drug unloaded scaffold, as assessed through MTT assay and Confocal imaging with MC3T3-E1 pre-osteoblast cells. Cell attachment and proliferation were certainly higher in the presence of drug loaded microspheres. Bone remodeling gene and protein expression were observed by real-time polymerase chain reaction and Western blot respectively. Simvastatin loaded scaffold exhibited the best results in every determination which was carried out.

In vitro and in vivo evaluation of porous PCL-PLLA 3D polymer scaffolds fabricated via salt leaching method for bone tissue engineering applications.

Three dimensional porous scaffolds composed of various ratios of polycaprolactone and poly(L-lactic acid) (PLLA) were prepared using salt leaching method for bone regeneration applications. Surfaces of the scaffolds were visualized using scanning electron microscope (SEM) and the combination of the polymers was confirmed by FT-IR. Addition of PLLA increased the porosity and pore sizes of the scaffolds and also the scaffolds' compressive strength initially. Osteoblast-like cells were used and it was found that the samples' cell biocompatibility was further promoted with the increase in PLLA content as observed via cell proliferation assays using MTT, gene expression with RT-PCR, and micrographs from SEM and confocal microscopy. Samples were then implanted into male rabbits for 2 months, and histological staining and micro-CT histomorphometry show that new bone formations were detected in the site containing the implants of the scaffolds and that bone regeneration was further promoted with the increased concentration of PLLA in the scaffold.

Poly(lactide-co-glycolide acid)/biphasic calcium phosphate composite coating on a porous scaffold to deliver simvastatin for bone tissue engineering.

In this study, simvastatin (SIM) drug incorporated poly(D,L-lactic-co-glycolide) (PLGA)/biphasic calcium phosphate (BCP) composite material (SPB) was coated on the BCP/ZrO2 (SPB-BCP/ZrO2) scaffold to enhance the mechanical and bioactive properties of the BCP/ZrO2 scaffold for bone engineering applications. The composite coating was prepared by combining different ratios of PLGA and BCP (1:2, 1:1, 2:1). After completion of the coating process, the compressive strength of the scaffolds was shown to increase with an increase in PLGA concentration from 8.5 ± 0.52 MPa for the SPB1-BCP/ZrO2 (1:2) to 11 ± 0.65 MPa for SPB3-BCP/ZrO2 (2:1) scaffolds when PLGA concentration was increased. Furthermore, the increase of PLGA in the coating composition corresponds to a decrease in porosity, degradation rate and weight loss of the scaffolds after 4 weeks. SIM release study demonstrated sustained release of the drug for the three kinds of scaffolds with improved biocompatibility. The increase of PLGA concentration also resulted in a lower release rate of SIM. Thus, the lower release rate of SIM brought upon by the increase of PLGA concentration further enhanced the performance of the scaffold in vitro making it a promising approach in the field of bone tissue regeneration.