Methacrylic-based nanogels for the pH-sensitive delivery of 5-Fluorouracil in the colon

N Ashwanikumar,1,* Nisha Asok Kumar,2,* S Asha Nair,2 GS Vinod Kumar11Chemical Biology, 2Cancer Research Programme, Rajiv Gandhi Center for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India *These authors contributed equally to this workAbstract: Methacrylic-based copolymers in drug-delivery systems demonstrate a pH-sensitive drug-releasing behavior in the colon. In this study, copolymers of methacrylic acid and 2-ethyl hexyl acrylate were prepared using a microemulsion polymerization technique. The purified copolymer was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. 5-Fluorouracil (5-FU) was entrapped within methacrylic-based copolymers by a solvent evaporation method. The size of the nanogels formed was characterized by transmission electron microscopy and atomic force microscopy. In vitro drug-release studies using phosphate-buffered saline at different pH levels demonstrated the sustained release of 5-FU and its pH dependence. Cell proliferation assay of a human colon tumor colon cancer cell line (HCT-116) was performed and showed that the nanogels containing 5-FU exhibited considerable cytotoxicity in comparison with free 5-FU. Cell uptake of the nanogels was also monitored using confocal microscopy. Western blot analysis and flow cytometry studies confirmed that the nanogels could be successfully used as an efficient vector for pH-sensitive and controlled delivery of drugs specifically targeted to the colon.Keywords: 5-FU, methacrylic polymer, colon cancer, nanoge

Interphase between skin, psyche, and society: A narrative review

Disorders of the skin affect the psyche of a person significantly. The interplay between internal and external world can be depicted through the various skin reactions in regard to psychological or physiological stimuli. Psychocutaneous illness could be exclusively psychological or stress related or due to strong psychogenic factors. As per biopsychosocial model, it could be primary, multifactorial, or secondary to disfigurement. Whichever is the condition, invariably stress is a major contributing factor in prognosis and onset of disorders of the skin. Self-explanation, myth, stigma, and diminished self-confidence often lead to depression and suicidality followed by active avoidance of the workplace, in turn, causing significant disability in the individual. The conflict between self-image and perceived image frequently causes fear of rejection leading to social anxiety, reduced self-confidence, interpersonal communication, and impaired sexual intimacy with a partner. Maladaptive sets of coping strategies such as alexithymia, shame proneness, avoidance, concealment, and escape are very common among the sufferers which impair the attachment with family and friends. Children are the extreme sufferers as they develop inferiority, low self-esteem, loss of body image, and social withdrawal leading to rejection from parents and faulty development of attachment pattern. Hence, disorders of the skin can lead to impaired coping, impaired compliance, limitations in quality of life, negative body image, and stigmatization which invariably cause psychological comorbidities such as depression, anxiety, phobia, and somatoform and adjustment disorders. Hence, there is a direct relationship between skin, mind, and society which we are going to explore in a detailed fashion to understand its impact on the psyche and the society

Self-assembling peptide nanofibers containing phenylalanine for the controlled release of 5-fluorouracil

Narayanan Ashwanikumar,1 Nisha Asok Kumar,2 Padma S Saneesh Babu,2 Krishnankutty C Sivakumar,3 Mithun Varghese Vadakkan,1 Parvathi Nair,1 Ilamathi Hema Saranya,1 Sivakumari Asha Nair,2 Gopalakrishnapillai S Vinod Kumar1 1Chemical Biology, Nano Drug Delivery Systems, Bio-Innovation Center, 2Cancer Research Programme, 3Distributed Information Sub-Centre (Bioinformatics Centre), Rajiv Gandhi Centre for Biotechnology, Poojappura, Thiruvananthapuram, Kerala, India Abstract: The study shows that RADA-F6 peptide with pH-responsive self-assembling nature can be effectively used as a drug delivery system for the sustained release of a potent anticancer drug 5-fluorouracil (5-FU) at basic pH. As 5-FU contains the aromatic pyrimidine ring, RADA-F6 system is suitable for entrapping an aromatic drug due to effective π–π stacking with phenylalanine and be able to show better controlled release behavior. The stability and controlled release nature of RADA-F6 in different conditions followed by 5-FU entrapment at in silico conditions was confirmed by molecular dynamics simulation taking RADA-16 as control. Cytotoxicity of the drug-loaded RADA-F6 was measured by MTT assay and cellular uptake by confocal microscopy. Physicochemical characterization and further Western blot analysis and flow cytometric studies confirm that RADA-F6 can be successfully used as an efficient vector for pH-sensitive, controlled 5-FU delivery system. Keywords: scaffold, drug delivery, nanofibrous, aromati

Author Correction: Naturally-occurring cholesterol analogues in lipid nanoparticles induce polymorphic shape and enhance intracellular delivery of mRNA

An amendment to this paper has been published and can be accessed via a link at the top of the paper