http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Johnson, Renjith P.,Jeong, Young‐,Il,Choi, Eunji,Chung, Chung‐,Wook,Kang, Dae Hwan,Oh, Sae‐,Ock,Suh, Hongsuk,Kim, Il WILEY‐VCH Verlag 2012 Advanced Functional Materials Vol.22 No.5
<P><B>Abstract</B></P><P>A series of synthetic polymer bioconjugate hybrid materials consisting of poly(2‐hydroxyethyl methacrylate) (p(HEMA)) and poly(<SMALL>l‐</SMALL>histidine) (p(His)) are synthesized by combining atom transfer radical polymerization of HEMA with ring opening polymerization of benzyl‐<I>N</I>‐carboxy‐<SMALL>L</SMALL>‐histidine anhydride. The resulting biocompatible and membranolytic p(HEMA)<SUB>25</SUB>‐<I>b</I>‐p(His)<SUB><I>n</I></SUB> (<I>n</I> = 15, 25, 35, and 45) polymers are investigated for their use as pH‐sensitive drug‐carrier for tumor targeting. Doxorubicin (Dox) is encapsulated in nanosized micelles fabricated by a self‐assembly process and delivered under different pH conditions. Micelle size is characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM) observations. Dox release is investigated according to pH, demonstrating the release is sensitive to pH. Antitumor activity of the released Dox is assessed using the HCT 116 human colon carcinoma cell line. Dox released from the p(HEMA)‐<I>b</I>‐p(His) micelles remains biologically active and has the dose‐dependent capability to kill cancer cells at acidic pH. The p(HEMA)‐<I>b</I>‐p(His) hybrid materials are capable of self‐assembling into nanomicelles and effectively encapsulating the chemotherapeutic agent Dox, which allows them to serve as suitable carriers of drug molecules for tumor targeting.</P>
Johnson, Renjith P.,Jeong, Young−,Il,John, Johnson V.,Chung, Chung-Wook,Kang, Dae Hwan,Selvaraj, Manickam,Suh, Hongsuk,Kim, Il American Chemical Society 2013 Biomacromolecules Vol.14 No.5
<P>A series of dual stimuli responsive synthetic polymer bioconjugate chimeric materials, poly(<I>N</I>-isopropylacrylamide)<SUB>55</SUB>-<I>block</I>-poly(<SMALL>l</SMALL>-histidine)<SUB><I>n</I></SUB> [p(NIPAM)<SUB>55</SUB>-<I>b</I>-p(His)<SUB><I>n</I></SUB>] (<I>n</I> = 50, 75, 100, 125), have been synthesized by employing reversible addition–fragmentation chain transfer polymerization of NIPAM, followed by ring–opening polymerization of α-amino acid <I>N</I>-carboxyanhydrides. The dual stimuli responsive properties of the resulting biocompatiable and membrenolytic p(NIPAM)<SUB>55</SUB>-<I>b</I>-p(His)<SUB><I>n</I></SUB> polymers are investigated for their use as a stimuli responsive drug carrier for tumor targeting. Highly uniform self-assembled micelles (∼55 nm) fabricated by p(NIPAM)<SUB>55</SUB>-<I>b</I>-p(His)<SUB><I>n</I></SUB> polymers display sharp thermal and pH responses in aqueous media. An anticancer drug, doxorubicin (Dox), is effectively encapsulated in the micelles and the controlled Dox release is investigated in different temperature and pH conditions. Antitumor effect of the released Dox is also assessed using the HepG2 human hepatocellular carcinoma cell lines. Dox molecules released from the [p(NIPAM)<SUB>55</SUB>-<I>b</I>-p(His)<SUB><I>n</I></SUB>] micelles remain biologically active and have stimuli responsive capability to kill cancer cells. The self-assembling ability of these hybrid materials into uniform micelles and their efficiency to encapsulate Dox makes them a promising drug carrier to cancer cells. The new chimeric materials thus display tunable properties that can make them useful for a molecular switching device and controlled drug delivery applications needing responses to temperature and pH for the improvement of cancer chemotherapy.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/bomaf6/2013/bomaf6.2013.14.issue-5/bm400089m/production/images/medium/bm-2013-00089m_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/bm400089m'>ACS Electronic Supporting Info</A></P>
Johnson, Renjith P,Uthaman, Saji,John, Johnson V,Lee, Hye Ri,Lee, Sang Joon,Park, Huiju,Park, In-Kyu,Suh, Hongsuk,Kim, Il American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.39
<P>A series of poly(ethylene glycol) methyl ether acrylate-block-poly(l-lysine)-block-poly(l-histidine) [p(PEGA)30-b-p(Lys)25-b-p(His)n] (n = 25, 50, 75, 100) triblock copolypeptides were designed and synthesized for tumoral pH-responsive intracellular release of anticancer drug doxorubicin hydrochloride (Dox). The tumoral acidic pH-responsive hybrid vesicles fabricated were stable at physiological pH 7.4 and could gradually destabilize in acidic pH as a result of pH-induced swelling of the p(His) block. The blank vesicles were nontoxic over a wide concentration range (0.01-100 관g/mL) in normal cell lines. The tumor acidic pH responsiveness of these vesicles was exploited for intracellular delivery of Dox. Vesicles efficiently encapsulated Dox, and pH-induced destabilization resulted in the controlled and sustained release of Dox in CT26 murine cancer cells, and dose-dependent cytotoxicity. The tumor-specific controlled release Dox from vesicles demonstrates this system represents a promising theranostic agent for tumor-targeted delivery.</P>
Johnson, Renjith P,Chung, Chung-Wook,Jeong, Young-Il,Kang, Dae Hwan,Suh, Hongsuk,Kim, Il Dove Medical Press 2012 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.7 No.-
<P><B>Background</B></P><P>5-Aminolevulinic acid (ALA) and its derivatives have been widely used in photodynamic therapy. The main drawback associated with ALA-based photodynamic therapy (ALA-PDT) and ALA fluorescence diagnosis results from the hydrophilic nature of ALA and lack of selectivity for tumor versus nontumor cells. The application of certain triggers, such as pH, into conventional sensitizers for controllable <SUP>1</SUP>O<SUB>2</SUB> release is a promising strategy for tumor-targeted treatment.</P><P><B>Methods</B></P><P>A series of pH-sensitive ALA-poly(L-histidine) [p(L-His)<SUB>n</SUB>] prodrugs were synthesized via ring opening polymerization of 1-benzyl-<I>N</I>-carboxy-L-histidine anhydride initiated by the amine hydrochloride group of ALA itself. As an alternative to ALA for PDT, the synthesized prodrugs were used to treat a cultured human colon cancer HCT116 cell line under different pH conditions. The effect of ALA-p(L-His)<SUB>n</SUB> derivatives was evaluated by monitoring the fluorescence intensity of protoporphyrin IX, and measuring the cell survival rate after suitable light irradiation.</P><P><B>Results</B></P><P>The cytotoxicity and dark toxicity of ALA and synthesized ALA-p(L-His) derivatives in HEK293T and HCT116 cells in the absence of light at pH 7.4 and 6.8 shows that the cell viability was relatively higher than 100%. ALA-p(L-His)<SUB>n</SUB> showed high phototoxicity and selectivity in different pH conditions compared with ALA alone. Because the length of the histidine chain increases in the ALA-p(L-His)<SUB>n</SUB> prodrugs, the PDT effect was found to be more powerful. In particular, high phototoxicity was observed when the cells were treated with ALA-p(L-His)<SUP>15</SUP>, compared with treatment using ALA alone.</P><P><B>Conclusion</B></P><P>The newly synthesized ALA-p(L-His)<SUB>n</SUB> derivatives are an effective alternative to ALA for enhancing protoporphyrin IX production and the selectivity of the phototoxic effect in tumor cells.</P>
Sarath C. Renjith,Kijung Park,Gül E. Okudan Kremer 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.2
Additive manufacturing has emerged as an integral part of modern manufacturing because of its unique capabilities in various application domains. As efforts to effectively apply additive manufacturing, design for additive manufacturing (DfAM) has risen to provide a set of guidelines based on a practical design framework or a methodology during the product design process of additive manufacturing. However, most existing DfAM methods do not effectively consider the capabilities of extant additive manufacturing technologies in the early design stages, and therefore it is hard to map functional requirements from customer needs onto a product design for additive manufacturing. Moreover, available DfAM methods tend to rely on the direct application of a specific decision method rather than a systematic approach with appropriate deployment and transformation of available design decision methods considering the additive manufacturing environment. Consequently, existing DfAM methods lack suitability for use by additive manufacturing novices. To tackle these issues, this study develops a design framework for additive manufacturing through the integration of axiomatic design and theory of inventive problem-solving (TRIZ). This integrated approach is effective because the axiomatic design approach can be used to systematically define and analyze a design problem, while the TRIZ problem-solving approach combined with an additive manufacturing database can be used as an idea generation tool to generate innovative solutions for the design problem. A case study for a housing cover redesign is presented to apply and validate the proposed design framework.
Kanna Rishi Mugesh,Renjith Karukayil Ramakrishnan,Shetty Ajoy Prasad,Rajasekaran Shanmuganathan 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.5
Study Design: Retrospective study.Purpose: Postoperative wound complications occurring after transforaminal lumbar interbody fusion (TLIF) are unique, as they can involve different tissue zones (subcutaneous, subfascial, osseous, peri-implant, and disc). Overview of Literature: Management of postoperative infections occurring after TLIF remains controversial in the context of retention or removal of implants.Methods: A total of 1,279 consecutive patients (1,520 segments) who underwent TLIF with a minimum follow-up of 1 year were analyzed. Patients with wound complications were classified anatomically into the following five types: type 1, suprafascial necrosis; type 2, wound dehiscence; type 3, pus around screws and rods; type 4, bone marrow edema; and type 5, pus in the disc space. Details pertaining to clinicoradiological and laboratory findings and management were also recorded.Results: Of the 62 patients (4.8%) with wound complications, there were seven patients in type 1, 35 in type 2, 10 in type 3, four in type 4, and six in type 5. Patients in types 1 and 2 manifested delayed wound healing and were systemically well. In type 1, five patients were managed with resuturing and two were managed conservatively. In type 2, all patients had wound gaping and were managed by debridement, whereas three patients required vacuum-assisted closure. Patients in type 3 had severe back pain and fever, with demonstrable pus around the screw site. Tissue culture identified organisms in 90% of the patients. Patients in type 4 presented with increasing back pain, and magnetic resonance imaging revealed vertebral bone marrow edema. Those in type 5 had severe back pain and fever, with demonstrable pus in the disc space. Patients in types 3–5 required debridement, implant revision/retention, and long-term antibiotics.Conclusions: The new anatomical classification of surgical site infections could help grade the severity of infection and provide tangible treatment guidelines, resulting in better infection clearance and patient outcomes.
Temperature profile and visible flame length of blended pool fires at quiescent air conditions
Sivi Varghese,V. R. Renjith 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5
Alcohol-derived biofuels are used as an alternative fuel source instead of petroleum-based fuels. There is a need to understand the fire behavior of these blended alcohol biofuels. Twelve laboratory-scale pool fire experimental tests were conducted at quiescent ambient air on n-propanol, diesel, and mixtures to understand the burning characteristics, like burning rate, flame temperature, and flame height. The burning rate of pure and blended fuels was estimated by two methods and compared. Visual images of fire were analyzed, and it was found that the maximum visible flame height of all fuels is nearly three-times the pool diameter. Centerline flame temperature is highest for n-propanol pool fires compared with diesel and its blends. A dimensionless temperature parameter φ makes a linear relationship with dimensionless vertical height for pure and binary mixtures. These combustion characteristics of blended fuel pool fire help ensure the safety of blended fuel handling, transportation, and storage.