Enhanced properties of nickel-silver codoped hydroxyapatite for bone tissue engineering: Synthesis, characterization, and biocompatibility evaluation

Hydroxyapatite (HAp) is the most well-known bioceramic and widely utilized in bone tissue regeneration. Hydroxyapatite is biocompatible and bioactive however, it lacks osteogenesis, angiogenesis, and antibacterial properties. In the current study, we synthesized and evaluated a novel nickel (Ni) and silver (Ag) codoped hydroxyapatite (HAp) in comparison to undoped HAp and individually doped HAp samples. Extensive physicochemical characterizations like XRD, TEM, FE-SEM/EDS, FTIR, Raman spectroscopy, and TGA were performed, confirming the crystal structure and morphology of the synthesized HAp samples. All HAp samples exhibited elongated spherical-like nanoparticle morphologies with lengths between 34 and 44 nm and widths between 21 and 26 nm. The presence of dopant atoms, Ag and Ni, were observed in the doped/codoped HAp samples by EDS elemental mapping. Biocompatibility assessments using pre-osteoblast cells indicated high cell viability for all the doped and undoped HAp samples. Osteoinduction potential through alkaline phosphatase (ALP) activity measurements and alizarin red S (ARS) staining revealed enhanced calcium deposition in the presence of Ni-Ag codoped HAp compared to other HAp samples and control groups. This highlights the importance of Ni-Ag co-doping in promoting osteogenesis, surpassing the effects of silver doped HAp and nickel doped HAp. The potential of this novel Ni-Ag codoped HAp to induce osteogenesis in pre-osteoblast cells makes it a promising material for various applications in bone tissue engineering.

Polysaccharide-bioceramic composites for bone tissue engineering: A review

Limitations associated with conventional bone substitutes such as autografts, increasing demand for bone grafts, and growing elderly population worldwide necessitate development of unique materials as bone graft substitutes. Bone tissue engineering (BTE) would ensure therapy advancement, efficiency, and cost-effective treatment modalities of bone defects. One way of engineering bone tissue scaffolds by mimicking natural bone tissue composed of organic and inorganic phases is to utilize polysaccharide-bioceramic hybrid composites. Polysaccharides are abundant in nature, and present in human body. Biominerals, like hydroxyapatite are present in natural bone and some of them possess osteoconductive and osteoinductive properties. Ion doped bioceramics could substitute protein-based biosignal molecules to achieve osteogenesis, vasculogenesis, angiogenesis, and stress shielding. This review is a systemic summary on properties, advantages, and limitations of polysaccharide-bioceramic/ion doped bioceramic composites along with their recent advancements in BTE.

On the application of hydrodynamic cavitation on a chip in cellular injury and drug delivery

Hydrodynamic cavitation (HC) is a phase change phenomenon, where energy release in a fluid occurs upon the collapse of bubbles, which form due to the low local pressures. During recent years, due to advances in lab-on-a-chip technologies, HC-on-a-chip (HCOC) and its potential applications have attracted considerable interest. Microfluidic devices enable the performance of controlled experiments by enabling spatial control over the cavitation process and by precisely monitoring its evolution. In this study, we propose the adjunctive use of HC to induce distinct zones of cellular injury and enhance the anticancer efficacy of Doxorubicin (DOX). HC caused different regions (lysis, necrosis, permeabilization, and unaffected regions) upon exposure of different cancer and normal cells to HC. Moreover, HC was also applied to the confluent cell monolayer following the DOX treatment. Here, it was shown that the combination of DOX and HC exhibited a more pronounced anticancer activity on cancer cells than DOX alone. The effect of HC on cell permeabilization was also proven by using carbon dots (CDs). Finally, the cell stiffness parameter, which was associated with cell proliferation, migration and metastasis, was investigated with the use of cancer cells and normal cells under HC exposure. The HCOC offers the advantage of creating well-defined zones of bio-responses upon HC exposure simultaneously within minutes, achieving cell lysis and molecular delivery through permeabilization by providing spatial control. In conclusion, micro scale hydrodynamic cavitation proposes a promising alternative to be used to increase the therapeutic efficacy of anticancer drugs.

Anaplastic thyroid carcinoma presenting with gastric metastasis: a case report

INTRODUCTION

Anaplastic thyroid carcinoma (ATC) has the most aggressive progression among thyroid malignancies. Most of the patients have metastasis, especially to the lungs, liver and regional lymph nodes, at the time of diagnosis. Gastrointestinal tract metastasis of ATC has been rarely reported. We report a case who presented with gastrointestinal bleeding and was diagnosed with ATC accompanied with gastric, skin, lung and adrenal gland metastases.

CASE REPORT

A 72-year-old male patient presented with one month history of neck mass, weight loss and weakness and three-day-history of melena. On examination his thyroid gland was tender on palpation and hyperplasic, multiple, painful, solid, and fixed nodules were palpated.Ultrasonographic neck examination demonstrated an enlarged thyroid gland and multiple hypoechoic nodules including cystic degenerative areas; the largest 28 x 23 mm in size. Thyroid fine needle aspiration biopsy was performed and biopsy results indicated ATC. Gastroscopy, performed due to the gastrointestinal bleeding, detected a 4 x 6 mm polypoid lesion on sternal pili of the gastric cardia and histopathological examination of its biopsy demonstrated metastasis of ATC.

CONCLUSION

We reported a case of ATC with gastric, skin, lung and adrenal gland metastases, initially presenting with gastrointestinal bleeding due to the gastric metastasis. Hippokratia 2015, 19 (1): 85-87.

The impact of fasting during Ramadan on the glycemic control of patients with type 2 diabetes mellitus

BACKGROUND

Millions of Muslims fast from dawn until dusk during the annual Islamic holy month of Ramadan. Most of the studies evaluating biochemical changes in diabetic patients during Ramadan showed little changes in the glycemic control. In this study, our aim was to assess the impact of fasting during Ramadan on glycemic control in patients with type 2 diabetes.

METHODS AND DESIGN

We examined 122 patients with type 2 diabetes (82 female, 40 male, age 56.93 ± 9.57 years) before and after the Ramadan. 66.4% of the patients were treated with oral antidiabetic (OAD) alone, 6.5% with a combination of insulin plus OAD and 19.7% with insulin alone. 88 of 122 patients fasted during Ramadan (26.98 ± 5.93 days). Weight, body mass index (BMI), waist circumference, blood pressure, fasting plasma glucose (FPG), postprandial glucose (PPG), fructosamine, HbA1c, fasting insulin and lipid parameters were measured.

RESULTS

The frequencies of both severe hyperglycemia and hypoglycemia were higher in the fasting group, but the difference was not significant (p=0.18). Weight, BMI, waist circumference, blood pressure, FPG (143.38 ± 52.04 vs. 139.31 ± 43.47 mg/dl) PPG (213.40 ± 98.56 vs. 215.66+109.31 mg/dl), fructosamine (314.18 ± 75.40 vs. 314.49 ± 68.36 µmol/l), HbA1c (6.33 ± 0.98 vs. 6.22 ± 0.92%) and fasting insulin (12.61 ± 8.94 vs. 10.51 ± 6.26 µU/ml) were unchanged in patients who fasted during Ramadan. Microalbuminuria significantly decreased during Ramadan (132.85 ± 197.11 vs. 45.03 ± 73.11 mg/dl).

CONCLUSIONS

In this study, we concluded that fasting during Ramadan did not worsen the glycemic control of patients with type 2 diabetes.

The importance of anti-insulin antibody in patients with type 1 diabetes mellitus treated with continuous subcutaneous insulin infusion or multiple daily insulin injections therapy

To investigate the influence of two insulin administration modalities, continuous subcutaneous insulin infusion (CSII) and multiple daily insulin injections (MDI) therapy with insulin analogues, on the development of insulin antibodies (IAs) in patients with type 1 diabetes mellitus and to assess the impact of IAs on glucose control and hypoglycaemia. 96 patients with type 1 diabetes mellitus treated with CSII (n = 48) or MDI (n = 48) were included in the study. Age, duration of diabetes, A1c, preprandial and postprandial blood glucose and hypoglycaemic events were compared between IA positive and negative patients. IA levels were higher in the CSII group (% 24.6 ± 14.2) than the MDI group (% 13.2 ± 9.9). Duration of diabetes and age were not associated with IA positiveness. While A1c, preprandial blood glucose and the frequency of hypoglycaemic events were similar in two groups, postprandial blood glucose was lower in IA positive group (P = 0.03). Patients with type 1 diabetes mellitus treated with CSII with insulin analogues had higher IA levels when compared to MDI therapy. However, the development of IAs did not impair the glycaemic control.