Bioactive Gum Arabic/κ-Carrageenan-Incorporated Nano-Hydroxyapatite Nanocomposites and Their Relative Biological Functionalities in Bone Tissue Engineering.

The present frontiers of bone tissue engineering are being pushed by novel biomaterials that exhibit phenomenal biocompatibility and adequate mechanical strength. In this work, we fabricated a ternary system incorporating nano-hydroxyapatite (n-HA)/gum arabic (GA)/κ-carrageenan (κ-CG) with varying concentrations, i.e., 60/30/10 (CHG1), 60/20/20 (CHG2), and 60/10/30 (CHG3). A binary system with n-HA and GA was also prepared with a ratio of 60/40 (HG) and compared with the ternary system. A rapid mineralization of the apatite layer was observed for the ternary systems after incubation in simulated body fluid (SBF) for 15 days as corroborated by scanning electron microscopy (SEM). CHG2 exhibited the maximum apatite layer deposition. Further, the nanocomposites were physicochemically analyzed by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and mechanical testing. Their results revealed a substantial interaction among the components, appropriate crystallinity, and significantly enhanced compressive strength and modulus for the ternary nanocomposites. The greatest mechanical strength was achieved by the scaffold containing equal amounts of GA and κ-CG. The cytotoxicity was evaluated by culturing osteoblast-like MG63 cells, which exhibited the highest cell viability for the CHG2 nanocomposite system. It was further supported by confocal microscopy, which revealed the maximum cell proliferation for the CHG2 scaffold. In addition, enhanced antibacterial activity, protein adsorption, biodegradability, and osteogenic differentiation were observed for the ternary nanocomposites. Osteogenic gene markers, such as osteocalcin (OCN), osteonectin (ON), and osteopontin (OPN), were present in higher quantities in the CHG2 and CHG3 nanocomposites as confirmed by western blotting. These results substantiated the pertinence of n-HA-, GA-, and κ-CG-incorporated ternary systems to bone implant materials.

Hydroxyapatite Nanoparticles Fortified Xanthan Gum-Chitosan Based Polyelectrolyte Complex Scaffolds for Supporting the Osteo-Friendly Environment.

Nanoparticle-reinforced polymer-based scaffolding matrices as artificial bone-implant materials are potential suitors for bone regenerative medicine as they simulate the native bone. In the present work, a series of bioinspired, osteoconductive tricomposite scaffolds made up of nano-hydroxyapatite (NHA) embedded xanthan gum-chitosan (XAN-CHI) polyelectrolyte complex (PEC) are explored for their bone-regeneration potential. The Fourier transform infrared spectroscopy studies confirmed complex formation between XAN and CHI and showed strong interactions between the NHA and PEC matrix. The X-ray diffraction studies indicated regulation of the nanocomposite (NC) scaffold crystallinity by the physical cues of the PEC matrix. Further results exhibited that the XAN-CHI/NHA5 scaffold, with a 50/50 (polymer/NHA) ratio, has optimized porous structure, appropriate compressive properties, and sufficient swelling ability with slower degradation rates, which are far better than those of CHI/NHA and other XAN-CHI/NHA NC scaffolds. The simulated body fluid studies showed XAN-CHI/NHA5 generated apatite-like surface structures of a Ca/P ratio ∼1.66. Also, the in vitro cell-material interaction studies with MG-63 cells revealed that relative to the CHI/NHA NC scaffold, the cellular viability, attachment, and proliferation were better on XAN-CHI/NHA scaffold surfaces, with XAN-CHI/NHA5 specimens exhibiting an effective increment in cell spreading capacity compared to XAN-CHI/NHA4 and XAN-CHI/NHA6 specimens. The presence of an osteo-friendly environment is also indicated by enhanced alkaline phosphatase expression and protein adsorption ability. The higher expression of extracellular matrix proteins, such as osteocalcin and osteopontin, finally validated the induction of differentiation of MG-63 cells by tricomposite scaffolds. In summary, this study demonstrates that the formation of PEC between XAN and CHI and incorporation of NHA in XAN-CHI PEC developed tricomposite scaffolds with robust potential for use in bone regeneration applications.

Trigonella foenum graecum seed polysaccharide coupled nano hydroxyapatite-chitosan: A ternary nanocomposite for bone tissue engineering.

Biomimetic nanocomposites containing hydroxyapatite and natural polymers are promising candidates for bone grafting. In this work, a tricomponent bioactive nanocomposite (nHA-CH-TFSP) assembling nano-hydroxyapatite (nHA), Chitosan (CH) and Trigonella foenum graecum seed polysaccharide (TFSP) was developed using co-precipitation method and investigated against bicomponent nHA-CH nanocomposite for bone tissue engineering. In contrast to nHA-CH nanocomposite, nHA-CH-TFSP nanocomposite exhibited rough and interconnected porous structure as revealed by SEM with the porosity (60.3 ±â€¯0.17) lying in the range of cancellous bone. The incorporation of TFSP in nHA-CH substantially enhanced the in vitro water absorption capacity and protein adsorption ability along with appropriate biodegradation rate. Additionally, the nHA-CH-TFSP nanocomposite exhibited superior antibacterial activity. The nHA-CH-TFSP evinced a compressive strength of 6.7 ±â€¯0.24 MPa and a compressive modulus of 100 ±â€¯1.4 MPa, which fulfill the strength requisite of cancellous bone and could provide strong support for the growth of osteoblasts cells. Furthermore, the in vitro bioactivity study demonstrated its excellent biomineralization capacity in comparison to nHA-CH. The synthesized nHA-CH-TFSP nanocomposite exhibited better cytocompatibility towards the MG-63 cells along with its haemocompatible nature. Taken together the results of the present study indicate that nHA-CH-TFSP could serve as a prospective analogue for bone tissue engineering.

Synergistic combination of natural bioadhesive bael fruit gum and chitosan/nano-hydroxyapatite: A ternary bioactive nanohybrid for bone tissue engineering.

In this work, we have explored the polysaccharide nature of bael fruit gum (BFG) motivated from the current findings about the substantial role of the polysaccharides in bone tissue engineering. The nanocomposite scaffold (CSH-BFG) was prepared by blending BFG, nano-hydroxyapatite (n-HA) and chitosan (CS) by co-precipitation approach and compared with n-HA and CS binary system (CSH). The analysis of different properties was carried out by SEM, TEM, FTIR, XRD and mechanical testing. The CSH-BFG scaffolds revealed a rough morphology and uniform distribution of particles along with strong chemical interactions among different components compared to the CSH scaffold. The incorporation of BFG in the scaffold resulted in significant increase of the compressive strength, compressive modulus, protein adsorption, biodegradation and swelling behaviour. The ternary system exhibited superior antibacterial activity against different bacterial pathogens compared to the binary system. The in vitro biomineralization ability was elucidated from the formation of thick apatite layer complementing the result of ARS study in the CSH-BFG nanocomposite. Our findings also revealed that BFG reinforced CSH nanocomposite exhibited enhanced cell adhesion and proliferation, osteogenic differentiation along with phenomenal cytocompatibility. Overall, our results signified that the fabricated CSH-BFG nanocomposite carries enormous potential to be applied in the bone remodelling procedures.

Myocardial infarction in a young man due to coronary artery aneurysms after an undiagnosed Kawasaki disease.

BACKGROUND: Kawasaki disease usually affects infants and young children. It often goes unrecognized in adults due to varying symptoms and lack of definite diagnostic criteria. OBJECTIVES: To describe the potential for acute myocardial infarction as a complication of antecedent Kawasaki Disease (KD). CASE REPORT: We describe a case of a 19-year-old man who presented to the Emergency Department (ED) with an acute myocardial infarction that was subsequently determined to be the result of previously untreated KD. CONCLUSION: Kawasaki disease can cause coronary complications in a teenager. A high level of suspicion in the ED can help in proper management of these patients.

Pattern of left ventricular hypertrophy seen on transthoracic echo in patients with hypertensive cardiomyopathy when compared with idiopathic hypertrophic cardiomyopathy.

OBJECTIVE: To explore the pattern of left ventricular hypertrophy caused by hypertension and to compare it with idiopathic hypertrophiccardiomyopathy. METHODS: The retrospective study was conducted at the echocardiography lab of Rashid Hospital, Dubai, from January 2009 to January 2010. Cases of 11 patients with significant left ventricular hypertrophy (septum > 15 mm) due to underlying hypertension were analysed and compared with 11 cases of idiopathic hypertrophic cardiography (septum >15mm) to assess the two groups with similar baseline echocardiographic features. Minitab software was used for statistical analysis. RESULTS: Although the pattern of hypertrophy in hypertensive patients was more concentric (n = 5; 45%), there was also asymmetrical septal hypertrophy in 4 (36%) cases, particularly the elderly with sigmoid shape septum. There was evidence of resting mid-cavity gradient due to reduced left ventricular end-systolic diametre in 4 (36%) cases. CONCLUSION: Although the equation between hypertension and left ventricular hypertrophy is more concentric, but it can be associated with left ventricular outflow tract obstruction and significant mid-cavity gradients similar to that seen in idiopathic hypertrophic cardiomyopathy.

Endomyocardial fibrosis causing stroke in a young man.

An Indian man in his late 30s presented with ischaemic stroke and eosinophilia of 711/mm(3). ECG showed first-degree heart block with ST depression and symmetrical T-wave inversions in the chest leads. Subsequently, the patient was further evaluated by echocardiography and cardiac MRI which identified the presence of endomyocardial fibrosis in the heart.