Assessment of human adipose-derived stem cell on surface-modified silicone implant to reduce capsular contracture formation.

Medical devices made from poly(dimethylsiloxane) (PDMS)-based silicone implants have been broadly used owing to their inert properties, biocompatibility, and low toxicity. However, long-term implantation is usually associated with complications, such as capsular contracture due to excessive local inflammatory response, subsequently requiring implant removal. Therefore, modification of the silicone surface to reduce a risk of capsular contracture has attracted increasing attention. Human adipose-derived stem cells (hASCs) are known to provide potentially therapeutic applications for tissue engineering, regenerative medicine, and reconstructive surgery. Herein, hASCs coating on a PDMS (hASC-PDMS) or itaconic acid (IA)-conjugated PDMS (hASC-IA-PDMS) surface is examined to determine its biocompatibility for reducing capsular contracture on the PDMS surface. In vitro cell cytotoxicity evaluation showed that hASCs on IA-PDMS exhibit higher cell viability than hASCs on PDMS. A lower release of proinflammatory cytokines is observed in hASC-PDMS and hASC-IA-PDMS compared to the cells on plate. Multiple factors, including in vivo mRNA expression levels of cytokines related to fibrosis; number of inflammatory cells; number of macrophages and myofibroblasts; capsule thickness; and collagen density following implantation in rats for 60 days, indicate that incorporated coating hASCs on PDMSs most effectively reduces capsular contracture. This study demonstrates the potential of hASCs coating for the modification of PDMS surfaces in enhancing surface biocompatibility for reducing capsular contracture of PDMS-based medical devices.

Spheroid Culture System Methods and Applications for Mesenchymal Stem Cells.

Owing to the importance of stem cell culture systems in clinical applications, researchers have extensively studied them to optimize the culture conditions and increase efficiency of cell culture. A spheroid culture system provides a similar physicochemical environment in vivo by facilitating cell-cell and cell-matrix interaction to overcome the limitations of traditional monolayer cell culture. In suspension culture, aggregates of adjacent cells form a spheroid shape having wide utility in tumor and cancer research, therapeutic transplantation, drug screening, and clinical study, as well as organic culture. There are various spheroid culture methods such as hanging drop, gel embedding, magnetic levitation, and spinner culture. Lately, efforts are being made to apply the spheroid culture system to the study of drug delivery platforms and co-cultures, and to regulate differentiation and pluripotency. To study spheroid cell culture, various kinds of biomaterials are used as building forms of hydrogel, film, particle, and bead, depending upon the requirement. However, spheroid cell culture system has limitations such as hypoxia and necrosis in the spheroid core. In addition, studies should focus on methods to dissociate cells from spheroid into single cells.

Gold Nanoparticles for Photothermal Cancer Therapy.

Gold is a multifunctional material that has been utilized in medicinal applications for centuries because it has been recognized for its bacteriostatic, anticorrosive, and antioxidative properties. Modern medicine makes routine, conventional use of gold and has even developed more advanced applications by taking advantage of its ability to be manufactured at the nanoscale and functionalized because of the presence of thiol and amine groups, allowing for the conjugation of various functional groups such as targeted antibodies or drug products. It has been shown that colloidal gold exhibits localized plasmon surface resonance (LPSR), meaning that gold nanoparticles can absorb light at specific wavelengths, resulting in photoacoustic and photothermal properties, making them potentially useful for hyperthermic cancer treatments and medical imaging applications. Modifying gold nanoparticle shape and size can change their LPSR photochemical activities, thereby also altering their photothermal and photoacoustic properties, allowing for the utilization of different wavelengths of light, such as light in the near-infrared spectrum. By manufacturing gold in a nanoscale format, it is possible to passively distribute the material through the body, where it can localize in tumors (which are characterized by leaky blood vessels) and be safely excreted through the urinary system. In this paper, we give a quick review of the structure, applications, recent advancements, and potential future directions for the utilization of gold nanoparticles in cancer therapeutics.

Serum Leptin Levels in Epileptic Children with Anticonvulsant Medication / 대한소아신경학회지

PURPOSE: A number of drugs are capable of changing body weight as a side effect. A number of neurotransmitter systems acting in several hypothalamic nuclei are pivotal to the storage regulation of body fat. Leptin is a protein encoded by the ob gene that is expressed in adipocyte. It regulates eating behavior by activating the action to the satiety center in the hypothalmus. The purpose of this study is to investigate the changes of serum leptin in children with epilepsy. METHODS: Serum leptin levels were measured in 43 epileptic patients (30 males, 13 females) receiving valproate or carbamazepine by radioimmunoassay. Thirty patients (19 males, 11 females, 10.0+/-5.0 years of age) were treated with valproate (VPA group) and 13 patients (11 males, 2 females, 9.1+/-4.0 years of age) were treated with carbamazepine (CBZ group). Obesity index and body mass index were calculated before and during anticonvulsant medications. RESULTS: 1) Body mass indices were significantly increased after VPA or CBZ medication; from 17.24+/-2.74 to 18.47+/-2.60 in VPA group, from 16.77+/-1.69 to 17.43+/-3.01 in CBZ group. 2) Obesity indices were increased without statistical significance after medication in both group. 3) Serum leptin levels were significantly higher in VPA group (4.54+/-4.77ng/ml) than CBZ group (2.47+/-2.26ng/ml). CONCLUSION: Body weight gain after VPA medication in susceptible individual might be related to a certain mechanism that elevates serum leptin level.