Maliheh Ghadiri

Curcumin as a wound healing agent.

Turmeric (Curcuma longa) is a popular Indian spice that has been used for centuries in herbal medicines for the treatment of a variety of ailments such as rheumatism, diabetic ulcers, anorexia, cough and sinusitis. Curcumin (diferuloylmethane) is the main curcuminoid present in turmeric and responsible for its yellow color. Curcumin has been shown to possess significant anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-mutagenic, anti-coagulant and anti-infective effects. Curcumin has also been shown to have significant wound healing properties. It acts on various stages of the natural wound healing process to hasten healing. This review summarizes and discusses recently published papers on the effects of curcumin on skin wound healing. The highlighted studies in the review provide evidence of the ability of curcumin to reduce the bodys natural response to cutaneous wounds such as inflammation and oxidation. The recent literature on the wound healing properties of curcumin also provides evidence for its ability to enhance granulation tissue formation, collagen deposition, tissue remodeling and wound contraction. It has become evident that optimizing the topical application of curcumin through altering its formulation is essential to ensure the maximum therapeutical effects of curcumin on skin wounds.

Biomedical applications of cationic clay minerals

Clay minerals have been a subject of interest owing to their ready availability in nature, a wide range of applications in various industries, and particularly their current and potential biomedical applications. They have been widely used for curative and protective purposes by humans since ancient times. Cationic clay minerals possess specific physicochemical characteristics such as high surface reactivity (high adsorption, cation exchange, colloidal or swelling capacity), good rheological behavior, high acid-absorbing capacity, and high dispersibility in water, which renders them suitable for various biomedical applications. Only a few reviews have exclusively discussed the biomedical applications of clay minerals, and to our knowledge, there is no updated review focusing on cationic clay minerals and their applications in pharmaceuticals, cosmetics, and regenerative medicine. In this review, we provide a brief introduction on natural, synthetic, and hybrid cationic clay minerals followed by a detailed discussion about their applications in biological systems.

Laponite clay as a carrier for in situ delivery of tetracycline

Although smectite clays have gained much interest in recent years as potential sustained local drug delivery vehicles, they have not been yet utilized or assessed as a local drug delivery device for treatment of periodontal disease. In this paper we showed that unique nanostructure and gel-formation ability of clay holds great promise as an effective drug carrier. In particular, we demonstrated the feasibility of using laponite XLG, a smectite clay, as a carrier for in situ delivery of tetracycline that can potentially be used in the treatment and prevention of periodontal disease. The intercalation of tetracycline between the layers of laponite at different acidic pHs and different concentrations of tetracycline was examined. The laponite–tetracycline composite was characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR) and differential thermal analysis (DTA). The results showed that, in a pH and concentration dependent manner, tetracycline can be intercalated between the layers of laponite nanoparticles. The release study in a simulated saliva solution demonstrated a sustained release of tetracycline from laponite over a 72 hour period. The antimicrobial activity of the released tetracycline was maintained and was not affected by the intercalation of tetracycline into the carrier (laponite) and its release from the carrier.

Conventional and Advanced Imaging in Neuromyelitis Optica

SUMMARY: Myelitis and optic neuritis are prototypic clinical presentations of both multiple sclerosis and neuromyelitis optica. Once considered a subtype of multiple sclerosis, neuromyelitis optica, is now known to have a discrete pathogenesis in which antibodies to the water channel, aquaporin 4, play a critical role. Timely differentiation of neuromyelitis optica from MS is imperative, determining both prognosis and treatment strategy. Early, aggressive immunosuppression is required to prevent the accrual of severe disability in neuromyelitis optica; conversely, MS-specific therapies may exacerbate the disease. The diagnosis of neuromyelitis optica requires the integration of clinical, MR imaging, and laboratory data, but current criteria are insensitive and exclude patients with limited clinical syndromes. Failure to recognize the expanding spectrum of cerebral MR imaging patterns associated with aquaporin 4 antibody seropositivity adds to diagnostic uncertainty in some patients. We present the state of the art in conventional and nonconventional MR imaging in neuromyelitis optica and review the place of neuroimaging in the diagnosis, management, and research of the condition.

Scalable surface area characterization by electrokinetic analysis of complex anion adsorption.

By means of the in situ electrokinetic assessment of aqueous particles in conjunction with the addition of anionic adsorbates, we develop and examine a new approach to the scalable characterization of the specific accessible surface area of particles in water. For alumina powders of differing morphology in mildly acidic aqueous suspensions, the effective surface charge was modified by carboxylate anion adsorption through the incremental addition of oxalic and citric acids. The observed zeta potential variation as a function of the proportional reagent additive was found to exhibit inverse hyperbolic sine-type behavior predicted to arise from monolayer adsorption following the Grahame-Langmuir model. Through parameter optimization by inverse problem solving, the zeta potential shift with relative adsorbate addition revealed a nearly linear correlation of a defined surface-area-dependent parameter with the conventionally measured surface area values of the powders, demonstrating that the proposed analytical framework is applicable for the in situ surface area characterization of aqueous particulate matter. The investigated methods have advantages over some conventional surface analysis techniques owing to their direct applicability in aqueous environments at ambient temperature and the ability to modify analysis scales by variation of the adsorption cross section.

A novel approach to enhance protein adsorption and cell proliferation on hydroxyapatite: citric acid treatment

Hydroxyapatite (HA) is a promising carrier for delivery of therapeutic proteins, especially bone morphogenetic proteins (BMPs), due to the affinity between the amino and carboxyl groups of proteins and the calcium and phosphate of HA. The main challenge of employing HA as a protein carrier is the burst release profile of protein. In this study, we developed a strategy to improve the protein loading capacity of HA and to sustain protein release from HA by immobilizing COO− groups onto the HA surface. HA particles were precipitated in presence of different amounts of citric acid (CA). The physico-chemical properties (crystallinity, surface area and surface charge) of CA-treated HA (CA–HA) were significantly changed compared to those of the unmodified HA. CA–HA demonstrated significantly higher affinity towards lysozyme, in which the lysozyme adsorption increased by increasing the concentration of CA during the HA preparation. Using the optimized parameters obtained from lysozyme adsorption, the results demonstrated that functionalizing HA with CA significantly increased the amount of BMP-2 loaded onto HA and prolonged its release profile. The in vitro results showed that the CA–HA is not toxic and indeed citric ions on HA shift the surface charge towards negative value, which promoted osteoblast-like cell proliferation on HA.

Layered silicate clay functionalized with amino acids: wound healing application

Natural materials such as “healing clays” in mud spas have been used for healing of skin ailments and wounds since prehistoric times. In this study, laponite, a synthetic clay mineral with similar properties to natural healing clays has been functionalized with different amino acids for the purpose of wound dressing application. Physico-chemical properties of prepared laponite/amino acid gels were characterised using various analytical methods. X-ray diffraction and thermogravimetric analysis confirmed the presence of these amino acids in the prepared materials. The release profile of amino acid in simulated wound exudate fluid demonstrated the highest release from laponite/lysine groups with up to 50% of the intercalated lysine released. The effect of the extracts (obtained from the prepared laponite/amino acid gels) was tested on human skin fibroblast. Cell proliferation, oxidative stress, anti-oxidant properties, and in vitro wound healing (scratch assay model) were assessed. The extracts obtained from laponite alone and laponite combined with arginine, lysine and leucine promoted fibroblast proliferation whereas the extract from laponite/glutamic acid significantly inhibited cell proliferation. Based on the in vitro results presented in this work, laponite/arginine, laponite/leucine and laponite/lysine can be potentially applied as a wound dressing to promote the healing process.

Cell-based therapies for the treatment of idiopathic pulmonary fibrosis (IPF) disease

ABSTRACT Introduction: During the last few decades, cell-based therapies have shown great potential to treat patients with lung diseases. It has been proposed that the administration of cells into an injured lung could be considered as a therapeutic method to repair and replace lost lung tissue. Using this method, transplanted cells with the ability to proliferate and differentiate into alveolar cells, have been suggested as a therapeutic strategy for IPF treatment. Areas covered: In this review, the latest investigations using various types of cells for IPF therapy have been presented. The cells studied for cell-based therapies in IPF are lung alveolar epithelial cells, lung resident stem cells and exogenous adult stem cells such as MSCs. Expert opinion: After many years of investigation, the use of cell-based therapies to treat IPF is still at the experimental phase. Problems include bioethical issues, safety of cell transplantation, routes of delivery and the dose and timing of administration. Further investigations are necessary to establish the best strategy for using cell-based therapies effectively for the treatment of IPF.

A mini-review on novel intraperiodontal pocket drug delivery materials for the treatment of periodontal diseases

Periodontal disease is defined as chronic inflammatory condition characterized by the destruction of the periodontal tissues causing loss of connective tissue attachment, loss of alveolar bone, and the formation of pathological pockets around the diseased teeth. The use of systemic antibiotics has been advocated for its treatment, but concerns emerged with respect to adverse drug reactions and its contribution to bacterial resistance. Thus local drug delivery devices have been developed that aim to deliver a high concentration of antimicrobial drugs directly to the affected site, while minimizing drug’s systemic exposure. A burst release of antimicrobial agent from carrier, resulting in a short and inadequate exposure of bacteria residing in periodontal pocket to the agent, remains the main challenge of current local delivery systems for the treatment of periodontal disease. This review aims to investigate and compare different local antimicrobial delivery systems with regard to the treatment of periodontal disease.

Investigation into physical–chemical variables affecting the manufacture and dissolution of wet-milled clarithromycin nanoparticles

Abstract A critical problem associated with poor water-soluble drugs is their low and variable bioavailability, which is derived from the slow dissolution and erratic absorption. Nano-formulation has been identified as one approach to enhance the rate and extent of drug absorption for compounds that demonstrate limited water solubility. This study aimed to investigate the physico-chemical variables that affect the manufacture, dissolution and consequent bioavailability of wet-milled clarithromycin (CLA) nanoparticles, a macrolide antibiotic. CLA nanoparticles were prepared using wet milling method followed by freeze-drying. Different stabilizer systems, consisting of surfactants and polymers alone or their combinations were studied to determine the optimum conditions for producing nano-sized CLA particles. In vitro characterizations of the CLA nanoparticles were performed using dynamic light scattering, X-ray powder diffraction, differential scanning calorimetry and dissolution efficiency test. Results showed that in general the wet milling process did not modify the crystallinity of the CLA nanoparticles. The poloxamers and polyvinyl alcohol (PVA) stabilizers resulted in nanoparticles with the smallest particle size and best dissolution rates. Furthermore, poloxamers F68 and F127, and PVA stabilizers demonstrated the best performance in increasing dissolution efficacy.