Hossein Mohammadi

Stem cells and injectable hydrogels: Synergistic therapeutics in myocardial repair.

One of the major problems in the treatment of cardiovascular diseases is the inability of myocardium to self-regenerate. Current therapies are unable to restore the hearts function after myocardial infarction. Myocardial tissue engineering is potentially a key approach to regenerate damaged heart muscle. Myocardial patches are applied surgically, whereas injectable hydrogels provide effective minimally invasive approaches to recover functional myocardium. These hydrogels are easily administered and can be either cell free or loaded with bioactive agents and/or cardiac stem cells, which may apply paracrine effects. The aim of this review is to investigate the advantages and disadvantages of injectable stem cell-laden hydrogels and highlight their potential applications for myocardium repair.

Engineered Hydrogels in Cancer Therapy and Diagnosis

Over the last decade, numerous investigations have attempted to clarify the intricacies of tumor development to propose effective approaches for cancer treatment. Thanks to the unique properties of hydrogels, researchers have made significant progress in tumor model reconstruction, tumor diagnosis, and associated therapies. Notably, hydrogel-based systems can be adjusted to respond to cancer-specific hallmarks and/or external stimuli. These well-known drug reservoirs can be used as smart carriers for multiple cargos, including both naked and nanoparticle-encapsulated chemotherapeutics, genes, and radioisotopes. Recent works have attempted to specialize hydrogels for cancer research; we comprehensively review this topic for the first time, synthesizing past results and defining paths for future work.

Ion-Doped Silicate Bioceramic Coating of Ti-Based Implant

Titanium and its alloy are known as important load-bearing biomaterials. The major drawbacks of these metals are fibrous formation and low corrosion rate after implantation. The surface modification of biomedical implants through various methods such as plasma spray improves their osseointegration and clinical lifetime. Different materials have been already used as coatings on biomedical implant, including calcium phosphates and bioglass. However, these materials have been reported to have limited clinical success. The excellent bioactivity of calcium silicate (Ca-Si) has been also regarded as coating material. However, their high degradation rate and low mechanical strength limit their further coating application. Trace element modification of (Ca-Si) bioceramics is a promising method, which improves their mechanical strength and chemical stability. In this review, the potential of trace element-modified silicate coatings on better bone formation of titanium implant is investigated.

Effect of ball milling time on the synthesis of nanocrystalline merwinite via mechanical activation and heat treatment

Abstract Nanocrystalline merwinite was successfully synthesized by mechanical activation of a mixture of magnesium hydroxide, calcium oxide and silica gel powders followed by heat treatment. The phase development and various physical properties were investigated as a function of milling time using X-ray diffraction, scanning electron microscopy, simultaneous thermal analysis, particle size analysis and transmission electron microscopy. The results showed that formation of merwinite in annealed powders was enhanced by increasing the milling time. Nanocrystalline merwinite powder with an average crystallite size of about 36 nm was obtained after 30 hours of ball milling and subsequent annealing in 900 °C for 1 hour.