Siddaramaiah Hatna

Microneedles (MNs) are tiny needle like structures used in drug delivery through layers of the skin. They are non-invasive and are associated with significantly less or no pain at the site of administration to the skin. MNs are excellent in delivering both small and large molecules to the subjects in need thereof. There exist several strategies for drug delivery using MNs, wherein each strategy has its pros and cons. Research in this domain lead to product development and commercialization for clinical use. Additionally, several MN-based products are undergoing clinical trials to evaluate its safety, efficacy, and tolerability. The present review begins by providing bird’s-eye view about the general characteristics of MNs followed by providing recent updates in the treatment of cancer using MNs. Particularly, we provide an overview of various aspects namely: anti-cancerous MNs that work based on sensor technology, MNs for treatment of breast cancer, skin carcinoma, prostate cancer, and MNs fabricated by additive manufacturing or 3 dimensional printing for treatment of cancer. Further, the review also provides limitations, safety concerns, and latest updates about the clinical trials on MNs for the treatment of cancer. Furthermore, we also provide a regulatory overview from the “United States Food and Drug Administration” about MNs.

The effect of cenosphere content on the performances of polyurethane/polystyrene (PU/PS, 90/10) interpenetrating polymer network (IPN) based green composites have been studied. The PU/PS IPNs have been prepared using castor oil, toluene diisocyanate and styrene. IPN/cenosphere composites have been prepared with different weight fractions viz., 0, 5, 10, 20 and 30 wt % of cenosphere. The prepared IPN composites have been characterized by physico – mechanical, chemical and thermal behavior. The tensile strength of unfilled IPN was 1.79 MPa and a significant improvement in tensile strength (34%) was noticed for 10% cenosphere loaded IPN composite. The swelling behavior of the composites has been studied in different organic solvents. Thermal characteristics of the composites have been measured using differential scanning calorimeter, thermogravimetric analysis and dynamic mechanical analysis (DMA). A slight improvement in thermal stability was noticed for filler loaded specimens. Morphological features of cryo-fractured IPN/cenosphere green composites have been analyzed using SEM.

To know the possibility of using Indian butter tree seed waste (mahua seed cake [MSC]) as a filler in the production of value‐added product such as polyurethane (PU) green composites, a series of PU composites have been fabricated with varying amounts, namely, 0, 2.5, 5.0, 7.5, and 10 wt%, of MSC, and their effects on the physicomechanical properties such as density, surface hardness, tensile strength, tensile modulus, and percentage elongation at break have been studied. It was found that the tensile strength of the green composites increased from 5.61 to 9.5 MPa and tensile modulus increased from 4.75 to 6.07 MPa with an increase in filler content from 2.5 to 7.5 wt%. The fabricated PU/MSC composites were characterized for structural behavior by Fourier transform infrared spectroscopy and for morphological behaviors by scanning electron microscopy. The chemical resistance of the green composites in different chemical environments has been investigated. The thermal stability and thermal degradation behaviors of composites were performed using thermogravimetric analysis. The microcrystalline parameters such as crystallite size (<N>) and lattice strain (g, %) have been computed using wide‐angle X‐ray scattering data. Based on these parameters, the structure–property relationship of the PU/MSC green composites has been established.

A series of castor oil (CO)‐based polyurethanes (PUs) were prepared by reacting CO with toluene diisocyanate (TDI) in the presence of coconut oil (CCO). The effects of CCO content viz., 5, 10, 20, and 30 wt% on the physico‐mechanical properties and chemical structure of PUs have been evaluated. The mechanical properties of the PUs indicate that the incorporation of CCO improves the tensile behaviors. The swelling behaviors of the PUs have been studied in organic solvents. The microcrystalline parameters, such as crystal size (<N>) and lattice disorder (g), of PUs have been estimated using wide‐angle X‐ray scattering studies. The results of tensile behaviors were corroborated with the microcrystalline parameters of the PUs. For a holistic view of the parameters involved in these systems, we have carried out the multivarient analysis that gives a better perspective of the result. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21390; View this article online atwileyonlinelibrary.com. DOI 10.1002/adv.21390

Polyurethane green composites with varying amounts viz., 0, 2.5, 5, 7.5 and 10 wt% of finely powdered ginger spent have been fabricated. The fabricated polyurethane/ginger spent green composites have been performed for mechanical properties such as surface hardness and tensile behaviours. The swelling behavior of the composites has been studied in different organic solvents. Improvement in tensile behaviors of the polyurethane/ginger spent composites were noticed up to 7.5 wt% of ginger spent content. Thermogravimetric analysis of the green composites has been carried out in order to determine the thermal stability and their mode of thermal degradation behaviour. The thermogravimetric analysis curves of polyurethane/ginger spent composites indicated three-step thermal degradation processes, suffers no weight loss up to 193℃ and completely degrades at around 540℃. Thermal degradation kinetic parameters such as energy of activation (E_a) have been calculated for the green composites using two mathematical models namely Coats–Redfern and Broido’s models. The microcrystalline parameters such as crystal size () and lattice strain have been computed using wide-angle X-ray scattering data. The structure-property relationship of the polyurethane/ginger spent composites has been established on the basis of these parameters.