Bioactive nano-fibrous scaffold for vascularized craniofacial bone regeneration

There has been a growing demand for bone grafts for correction of bone defects in complicated fractures or tumors in the craniofacial region. Soft flexible membrane like material that could be inserted into defect by less invasive approaches; promote osteoconductivity and act as a barrier to soft tissue in growth while promoting bone formation is an attractive option for this region. Electrospinning has recently emerged as one of the most promising techniques for fabrication of extracellular matrix (ECM) like nano-fibrous scaffolds that can serve as a template for bone formation. To overcome the limitation of cell penetration of electrospun scaffolds and improve on its osteoconductive nature, in this study, we fabricated a novel electrospun composite scaffold of polyvinyl alcohol (PVA) - poly (ε) caprolactone (PCL) - Bioceramic (HAB), namely, PVA-PCL-HAB. The scaffold prepared by dual electrospinning of PVA and PCL with HAB overcomes reduced cell attachment associated with hydrophobic poly (ε) caprolactone (PCL) by combination with a hydrophilic polyvinyl alcohol (PVA) and the bioceramic (HAB) can contribute to enhance osteo-conductivity. We characterized the physicochemical and biocompatibility properties of the new scaffold material. Our results indicate PVA-PCL-HAB scaffolds support attachment and growth of stromal stem cells; (human bone marrow skeletal (mesenchymal) stem cells (hMSC) and dental pulp stem cells (DPSC)). In addition, the scaffold supported in vitro osteogenic differentiation and in vivo vascularized bone formation. Thus, PVA-PCL-HAB scaffold is a suitable potential material for therapeutic bone regeneration in dentistry and orthopaedics

Sodium yttrium fluoride based upconversion nano phosphors for biosensing

In the present study, NaYF4-Yb3+/Er3+ having the composition NaYF4-18%Yb3+/2%Er3+ and NaYF4-20%Yb3+/2%Er3+ with and without the addition of PVP (polyvinyl pyrolidone) have been synthesised by a solution method using NaF, yttrium nitrate, ytterbium nitrate and erbium nitrate as precursors. Upconversion spectra of prepared nanomaterial under 980 nm laser excitation have been studied. The variation in upconversion spectra with new born calf serum and myoglobin has been studied. Myoglobin (Mb) may be helpful when used in conjunction with other cardiac markers for rapid determination of acute myocardial ischemia, especially in patients with a typical chest pain or nonspecific ECG changes. The variation of UC fluorescence with addition of Mb indicates the suitability of using NaYF4 based UC nanoparticles in cardiac marker detection. The detailed study is currently under progress

Occurrence of vancomycin-resistant Staphylococcus aureus in the oral cavity of patients with dental caries

Oral streptococci are the major group of microbes isolated from oral microflora. They represent frequent pathogens of infective endocarditis (IE), and it is assumed that in most of the cases oral streptococci are acquired via mucosa layer of oral cavity. Staphylococcus aureus is also frequently isolated from IE as it accounts for 20%–30% of all cases. Vancomycin has been the most reliable therapeutic agent against infections caused by methicillin-resistant S. aureus (MRSA). The main objective of this study was to examine the occurrence of S. aureus species in dental caries specimens. Antimicrobial susceptibility testing of S. aureus to four antibiotics namely vancomycin, linezolid, teicoplanin, and daptomycin was performed. Detection of vancomycin resistance was conducted using polymerase chain reaction. Among the tested 150 strains, 98 were MRSA and of that 54 were vancomycin sensitive and 27 were resistant. All 98 MRSA strains were positive for mecA and 36 yielded pvl, whereas 13 carried vanA and only 2 were positive for vanB. Majority of the isolates showed sensitivity toward daptomycin and linezolid. Strains of S. aureus exhibiting decreased susceptibility to different antibiotics like vancomycin, daptomycin, and linezolid severely compromise the therapeutic alternatives and require a considerable amount of time, public awareness, and integrative health-care strategies to prevent the emergence of resistance to these compounds

Ceramic Bone Graft Substitutes do not reduce donor-site morbidity in ACL reconstruction surgeries: a pilot study

Introduction: Anterior knee pain is a major problem following Bone-patellar-tendon-bone graft (BPTB) use in anterior cruciate ligament (ACL) reconstruction. We hypothesized that filling the donor defect sites with bone-graft substitute would reduce the anterior knee symptoms in ACL reconstruction surgeries. Material and Methods: Patients operated for ACL-deficient knee between March 2012 and August 2013 using BPTB graft were divided into two treatment groups. The patellar and tibial donor-site bony defects were filled-up with Hydroxyapatite–Bioglass (HAP:BG) blocks in the study group (n = 15) and no filler was used in the control group (n = 16). At 2 years, the clinical improvement was assessed using International Knee Documentation Committee (IKDC) score and donor-site morbidity was assessed by questionnaires and specific tests related to anterior knee pain symptoms. Results: Donor-site tenderness was present in 40% patients in the study group and 37.5% patients in the control group (p = 0.59). Pain upon kneeling was present in 33.3% patients in the study group and 37.5% patients in the control group (p = 0.55). Walking in kneeling position elicited pain in 40% patients in the study group and 43.8% in the control group (p = 0.56). The mean visual analogue score for knee pain was 3.0 in the study group and 3.13 in the control group, with no statistically significant difference (p = 0.68). Unlike control group, where a persistent bony depression defect was observed at donor sites, no such defects were observed in the study group. Conclusion: Filling the defects of donor sites with HAP:BG blocks do not reduce the anterior knee symptoms in patients with ACL reconstruction using autogenous BPTB graft

Self-Controlled Hyperthermia & MRI Contrast Enhancement via Iron Oxide Embedded Hydroxyapatite Superparamagnetic particles for Theranostic Application

Increasing effectiveness of cancer therapeutics requires a multipronged approach. Delivery of controlled hyperthermia in the ranges of 43 to 45 °C on site aided by superparamagnetic particles ensures cell death via the apoptosis pathway.We demonstrated the use of iron-oxide embedded hydroxyapatite (HAIO) superparamagnetic particles for delivery of controlled hyperthermia and contrast enhancement in MRI. To determine optimal hyperthermia delivery, we used 5 and 10 mg/mL concentrations of HAIO on various magnetic fields in alternating magnetic field (AMF) study. Time–temperature profile and specific loss power (SLP) data revealed that HAIO delivered precisely controlled temperature in contrast to superparamagnetic iron oxide nanoparticles (SPIONs). Earlier studies had demonstrated that HAIO concentrations of 0.5 to 3 mg/mL are cytocompatible. Exposure of HeLa cells to HAIO at a concentration of 2 mg/mL and applied field of 33.8 mT for a period of 30 min resulted in apoptosis induction in 75% of population. Significant cellular disruption was affirmed via FACS, ESEM and cLSM techniques. An aqueous phantom study and <i>in vitro</i> cell culture study evaluation indicated relaxivity of 50.92 mM^–1 s^–1 and good pixel intensity variation in MRI. The current study assesses the potential of HAIO to deliver controlled hyperthermia and act as a negative MRI contrast agent. Repeated experiments have confirmed enhanced utility of the technique in the burgeoning field of theranostics

Periapical tissue reaction to calcium phosphate root canal sealer in porcine model

Background: Calcium phosphate cements (CPC) are a group of biomaterials possessing wide scope of use in various branches of medical science. These materials have been proposed to be highly biocompatible and osteoconductive. This study is based on a newly developed CPC formulation (Chitra-CPC) and is aimed at the evaluation of its biocompatibility through an Endodontic Usage Test in a porcine study model. Objective: To evaluate the periapical tissue reaction to Chitra-CPC when used as a root canal sealer/filler material in comparison with a resin sealer, AH Plus (Dentsply). Materials and Methods: The procedure was done on porcine animal model following the ISO 7405 criteria. The material was implanted intentionally into the periapical area of 36 teeth through a root canal procedure carried out in six animals which were divided equally among 1-month and 3-month time periods. Results were based on the histological evaluation of the autopsied specimens after the prescribed time periods. Results: Mild to moderate periapical tissue reaction was found in Chitra-CPC samples belonging to the 1-month time period, whereas majority of the 3-month CPC samples showed an absence of inflammation. Samples of AH Plus in 1-month period showed severe to moderate inflammation, whereas 3-month AH Plus samples had a mild to moderate inflammation. Conclusions: Chitra-CPC is a biocompatible material