Bioengineering Department, Box 352255, University of Washington, Seattle, WA 98195, USA. firstname.lastname@example.org
This article reviews the composition and synthesis of hydrogels, the character of their absorbed water, and permeation of solutes within their swollen matrices. The most important properties of hydrogels relevant to their biomedical applications are also identified, especially for use of hydrogels as drug and cell carriers, and as tissue engineering matrices.
Mar Drugs. 2011 Dec ;9 (12):2572-604 22363241
Department of Life Sciences, University of Trieste, Via L. Giorgieri 1, Trieste, Italy. email@example.com
This review's main objective is to discuss some physico-chemical features of polysaccharides as intrinsic determinants for the supramolecular structures that can efficiently provide encapsulation of drugs and other biological entities. Thus, the general characteristics of some basic polysaccharides are outlined in terms of their conformational, dynamic and thermodynamic properties. The analysis of some polysaccharide gelling properties is also provided, including the peculiarity of the charged polysaccharides. Then, the way the basic physical chemistry of polymer self-assembly is made in practice through the laboratory methods is highlighted. A description of the several literature procedures used to influence molecular interactions into the macroscopic goal of the encapsulation is given with an attempt at classification. Finally, a practical case study of specific interest, the use of marine polysaccharide matrices for encapsulation of vaccines in aquaculture, is reported.
Rozaini Mohd Zohdi, Zuki Abu Bakar Zakaria, Norimah Yusof, Noordin Mohamed Mustapha, Muhammad Nazrul Hakim Abdullah
Department of Life Sciences, Faculty of Pharmacy, Universiti Teknologi MARA, 42300 Puncak Alam, Selangor, Malaysia.
A novel cross-linked honey hydrogel dressing was developed by incorporating Malaysian honey into hydrogel dressing formulation, cross-linked and sterilized using electron beam irradiation (25 kGy). In this study, the physical properties of the prepared honey hydrogel and its wound healing efficacy on deep partial thickness burn wounds in rats were assessed. Skin samples were taken at 7, 14, 21, and 28 days after burn for histopathological and molecular evaluations. Application of honey hydrogel dressings significantly enhanced (P < 0.05) wound closure and accelerated the rate of re-epithelialization as compared to control hydrogel and OpSite film dressing. A significant decrease in inflammatory response was observed in honey hydrogel treated wounds as early as 7 days after burn (P < 0.05). Semiquantitative analysis using RT-PCR revealed that treatment with honey hydrogel significantly (P < 0.05) suppressed the expression of proinflammatory cytokines (IL-1α, IL-1β, and IL-6). The present study substantiates the potential efficacy of honey hydrogel dressings in accelerating burn wound healing.
Encapsulation of curcumin in self-assembling peptide hydrogels as injectable drug delivery vehicles.
Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States.
Curcumin, a hydrophobic polyphenol, is an extract of turmeric root with antioxidant, anti-inflammatory and anti-tumorigenic properties. Its lack of water solubility and relatively low bioavailability set major limitations for its therapeutic use. In this study, a self-assembling peptide hydrogel is demonstrated to be an effective vehicle for the localized delivery of curcumin over sustained periods of time. The curcumin-hydrogel is prepared in-situ where curcumin encapsulation within the hydrogel network is accomplished concurrently with peptide self-assembly. Physical and in vitro biological studies were used to demonstrate the effectiveness of curcumin-loaded β-hairpin hydrogels as injectable agents for localized curcumin delivery. Notably, rheological characterization of the curcumin-loaded hydrogel before and after shear flow have indicated solid-like properties even at high curcumin payloads. In vitro experiments with a medulloblastoma cell line confirm that the encapsulation of the curcumin within the hydrogel does not have an adverse effect on its bioactivity. Most importantly, the rate of curcumin release and its consequent therapeutic efficacy can be conveniently modulated as a function of the concentration of the MAX8 peptide.
ACS Nano. 2011 Jun 28;5 (6):5094-9 21542633
Huaizhi Kang, Anna Carolina Trondoli, Guizhi Zhu, Yan Chen, Ya-Jen Chang, Haipeng Liu, Yu-Fen Huang, Xiaoling Zhang, Weihong Tan
Center For Research at the Bio/nano Interface, Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States.
A near-infrared light-responsive drug delivery platform based on Au-Ag nanorods (Au-Ag NRs) coated with DNA cross-linked polymeric shells was constructed. DNA complementarity has been applied to develop a polyacrylamide-based sol-gel transition system to encapsulate anticancer drugs into the gel scaffold. The Au-Ag NR-based nanogels can also be readily functionalized with targeting moieties, such as aptamers, for specific recognition of tumor cells. When exposed to NIR irradiation, the photothermal effect of the Au-Ag NRs leads to a rapid rise in the temperature of the surrounding gel, resulting in the fast release of the encapsulated payload with high controllability. In vitro study confirmed that aptamer-functionalized nanogels can be used as drug carriers for targeted drug delivery with remote control capability by NIR light with high spatial/temporal resolution.
Cancer Biology Research Center, Sanford Research/University of South Dakota, Sioux Falls, SD 57104, USA.
Here, we provide a comprehensive insight into current advances in the use of nanogel-mediated chemotherapy for cancer treatment. Nanogels are composed of cross-linked three-dimensional polymer chain networks that are formed via covalent linkages or self-assembly processes. The porosity between the cross-linked networks of nanogels not only provides an ideal reservoir for loading drugs, oligonucleotides and imaging agents, but also protects them from environmental degradation and hazards. Here, we focus mainly on novel synthetic strategies and key considerations in the design of nanogel-based drug delivery systems for controlled and targeted cancer therapeutic applications.
Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States.
Biocompatible hydrogels have great potentials in biomedical and biotechnological applications. In the current study, we reported a new naturally occurring protein motif that formed a transparent hydrogel when heated to 90 °C at a concentration as low as 0.4 mg/mL. The protein motif is the C-terminal soluble domain of an Escherichia coli inner membrane protein YajC (YajC-CT). We investigated the conformational change and self-assembly of the protein that lead to the formation of hydrogels using multiple methods. Atomic force microscopy studies of dilute gel samples revealed the presence of β-sheet-rich fibrils that were 2 to 3 nm in height and micrometers in length, which appeared to originate from homogeneous particles. On the basis of these observations, we proposed a three-step pathway of YajC-CT gelation. Hydrogels formed at different pH contained slightly different fibril structures. To our knowledge, this is the smallest hydrogel-forming globular protein module that has been characterized in detail. It may be useful as a model system in the elucidation of the mechanisms of protein fibrillation and gelation processes.
Pilot randomized trial for treatment of bacterial vaginosis using in situ forming metronidazole vaginal gel.
Department of Obstetrics and Gynecology, Faculty of Medicine, Assiut University, Assiut, Egypt. firstname.lastname@example.org
AIM To compare the efficacy of a novel vaginal delivery system for metronidazole (0.8% MTZ in situ gel) versus a conventional MTZ vaginal gel product in the treatment of bacterial vaginosis (BV). MATERIAL AND METHODS All consecutive patients who presented to a tertiary care hospital with symptoms suggestive of BV were approached to participate in the study. Forty-two eligible participants were randomly assigned to either MTZ in situ gel or a conventional vaginal gel product twice daily for 5 days. All participants were re-examined after one and 4 weeks of the beginning of treatment to ensure cure of infection and any side-effects. RESULTS Demographic criteria of the participants were comparable in the two treatment groups. The cure rate after one week from the treatment was 85% in the in situ gel group and 71.4% in the conventional vaginal gel group (P = 0.294), while after 4 weeks, the cure rate showed significant difference in the in situ gel group as compared to the conventional vaginal gel group (16/20 [80%]) and (9/19 [47.4%]), respectively (P = 0.034). CONCLUSION Pilot testing showed that in situ MTZ vaginal gel is more effective than the conventional vaginal gel for long-term cure of BV. These findings suggest a novel and efficient long-term treatment of BV.
Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States.
Cyclic poly(5-hydroxy-1-cyclooctene)(PACOE) was synthesized by ring-expansion metathesis polymerization (REMP), and thiol-ene chemistry was used to cross-link the internal double bonds in the PACOE backbone. This created a novel network material (gels formed from cyclic polymers) with unique structural units, where the cyclic PACOE main chains, which serve as secondary topological cross-linkages, were connected by primary intermolecular chemical cross-linkages. The resulting properties were notably different from those of traditional chemically cross-linked linear PACOE gels, whose gel fraction (GF) and modulus (G) increased while the swelling ratio (Q) decreased with increasing initial polymer concentration in the gel precursor solution (C(0)). For the gels formed from cyclic polymers, however, the GF, Q, and G all simultaneously increased as C(0) increased at the higher range. Furthermore, at the same preparation state (same C(0)), the swelling ability and the maximum strain at break of the gels formed from cyclic polymers were always greater than those of the gels formed from linear polymers, and these differences became more pronounced as C(0) increased.
J Tissue Eng. 2010 ;2010 :218142 21350642
Ye-Rang Yun, Jong Eun Won, Eunyi Jeon, Sujin Lee, Wonmo Kang, Hyejin Jo, Jun-Hyeog Jang, Ueon Sang Shin, Hae-Won Kim
Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan 330-714, Republic of Korea.
Fibroblast growth factors (FGFs) that signal through FGF receptors (FGFRs) regulate a broad spectrum of biological functions, including cellular proliferation, survival, migration, and differentiation. The FGF signal pathways are the RAS/MAP kinase pathway, PI3 kinase/AKT pathway, and PLCγ pathway, among which the RAS/MAP kinase pathway is known to be predominant. Several studies have recently implicated the in vitro biological functions of FGFs for tissue regeneration. However, to obtain optimal outcomes in vivo, it is important to enhance the half-life of FGFs and their biological stability. Future applications of FGFs are expected when the biological functions of FGFs are potentiated through the appropriate use of delivery systems and scaffolds. This review will introduce the biology and cellular functions of FGFs and deal with the biomaterials based delivery systems and their current applications for the regeneration of tissues, including skin, blood vessel, muscle, adipose, tendon/ligament, cartilage, bone, tooth, and nerve tissues.
Gold nanocages covered with thermally-responsive polymers for controlled release by high-intensity focused ultrasound.
Weiyang Li, Xin Cai, Chulhong Kim, Guorong Sun, Yu Zhang, Rui Deng, Miaoxin Yang, Jingyi Chen, Samuel Achilefu, Lihong V Wang, Younan Xia
Department of Biomedical Engineering, Washington University, St Louis, Missouri 63130, USA.
This paper describes the use of Au nanocages covered with smart, thermally-responsive polymers for controlled release with high-intensity focused ultrasound (HIFU). HIFU is a highly precise medical procedure that uses focused ultrasound to heat and destroy pathogenic tissue rapidly and locally in a non-invasive or minimally invasive manner. The released dosage could be remotely controlled by manipulating the power of HIFU and/or the duration of exposure. We demonstrated localized release within the focal volume of HIFU by using gelatin phantom samples containing dye-loaded Au nanocages. By placing chicken breast tissues on top of the phantoms, we further demonstrated the feasibility of this system for controlled release at depths up to 30 mm. Because it can penetrate more deeply into soft tissues than near-infrared light, HIFU is a potentially more effective external stimulus for rapid, on-demand drug release.
Other papers by authors:
ACS Nano. 2012 Jul 17;: 22804625
Multiplexed Enrichment and Detection of Malarial Biomarkers using a Stimuli-Responsive Iron Oxide and Gold Nanoparticle Reagent System.
There is a need for simple yet robust biomarker and antigen purification and enrichment strategies that are compatible with current rapid diagnostic modalities. Here, a stimuli-responsive nanoparticle system is presented for multiplexed magneto-enrichment and non-instrumented lateral flow strip detection of model antigens from spiked pooled plasma. The integrated reagent system allows purification and enrichment of the gold-labeled biomarker half-sandwich that can be applied directly to lateral flow test strips. A linear diblock copolymer with a thermally-responsive poly(N-isopropylacrylamide)(pNIPAm) segment and a gold-binding block composed of NIPAm-co-N,N-dimethylaminoethylacrylamide (DMAEAm) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization. The diblock copolymer was used to functionalize gold nanoparticles (AuNPs), with subsequent bioconjugation to yield thermally-responsive pNIPAm-AuNPs that were co-decorated with streptavidin. These AuNPs efficiently complexed biotinylated capture antibody reagents that were bound to picomolar quantities of pan-aldolase and Plasmodium Falciparum histidine rich protein 2 (PfHRP2) in spiked pooled plasma samples. The gold-labeled biomarker half-sandwich was then purified and enriched using 10 nm thermally-responsive magnetic nanoparticles that were similarly decorated with pNIPAm. When a thermal stimulus was applied in conjunction with a magnetic field, co-aggregation of the AuNP-half-sandwiches with the pNIPAm-coated iron oxide nanoparticles created large aggregates that were efficiently magnetophoresed and separated from bulk serum. The purified biomarkers from a spiked pooled plasma sample could be concentrated 50-fold into a small volume and applied directly to a commercial multi-plexed lateral flow strip to dramatically improve the signal-to-noise ratio and test sensitivity.
PLoS One. 2012 ;7 (3):e32893 22457723
Biosafety of non-surface modified carbon nanocapsules as a potential alternative to carbon nanotubes for drug delivery purposes.
Alan C L Tang, Gan-Lin Hwang, Shih-Jung Tsai, Min-Yao Chang, Zack C W Tang, Meng-Da Tsai, Chwan-Yao Luo, Allan S Hoffman, Patrick C H Hsieh
Institute of Clinical Medicine, National Cheng Kung University & Hospital, Tainan, Taiwan.
BACKGROUND Carbon nanotubes (CNTs) have found wide success in circuitry, photovoltaics, and other applications. In contrast, several hurdles exist in using CNTs towards applications in drug delivery. Raw, non-modified CNTs are widely known for their toxicity. As such, many have attempted to reduce CNT toxicity for intravenous drug delivery purposes by post-process surface modification. Alternatively, a novel sphere-like carbon nanocapsule (CNC) developed by the arc-discharge method holds similar electric and thermal conductivities, as well as high strength. This study investigated the systemic toxicity and biocompatibility of different non-surface modified carbon nanomaterials in mice, including multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), carbon nanocapsules (CNCs), and C ₆₀ fullerene (C ₆₀). The retention of the nanomaterials and systemic effects after intravenous injections were studied. METHODOLOGY AND PRINCIPAL FINDINGS MWCNTs, SWCNTs, CNCs, and C ₆₀ were injected intravenously into FVB mice and then sacrificed for tissue section examination. Inflammatory cytokine levels were evaluated with ELISA. Mice receiving injection of MWCNTs or SWCNTs at 50 µg/g b.w. died while C ₆₀ injected group survived at a 50% rate. Surprisingly, mortality rate of mice injected with CNCs was only at 10%. Tissue sections revealed that most carbon nanomaterials retained in the lung. Furthermore, serum and lung-tissue cytokine levels did not reveal any inflammatory response compared to those in mice receiving normal saline injection. CONCLUSION Carbon nanocapsules are more biocompatible than other carbon nanomaterials and are more suitable for intravenous drug delivery. These results indicate potential biomedical use of non-surface modified carbon allotrope. Additionally, functionalization of the carbon nanocapsules could further enhance dispersion and biocompatibility for intravenous injection.
ACS Nano. 2012 Apr 24;6 (4):2960-8 22404424
In situ supramolecular assembly and modular modification of hyaluronic acid hydrogels for 3D cellular engineering.
Kyeng Min Park, Jeong-A Yang, Hyuntae Jung, Junseok Yeom, Ji Sun Park, Keun-Hong Park, Allan S Hoffman, Sei Kwang Hahn, Kimoon Kim
Center for Smart Supramolecules, Department of Chemistry, Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Nam-gu, Pohang, Kyungbuk 790-784, Korea.
A facile in situ supramolecular assembly and modular modification of biocompatible hydrogels were demonstrated using cucurbituril-conjugated hyaluronic acid (CB-HA), diaminohexane-conjugated HA (DAH-HA), and tags-CB for cellular engineering applications. The strong and selective host-guest interaction between CB and DAH made possible the supramolecular assembly of CB/DAH-HA hydrogels in the presence of cells. Then, the 3D environment of CB/DAH-HA hydrogels was modularly modified by the simple treatment with various multifunctional tags-CB. Furthermore, we could confirm in situ formation of CB/DAH-HA hydrogels under the skin of nude mice by sequential subcutaneous injections of CB-HA and DAH-HA solutions. The fluorescence of modularly modified fluorescein isothiocyanate (FITC)-CB in the hydrogels was maintained for up to 11 days, reflecting the feasibility to deliver the proper cues for cellular proliferation and differentiation in the body. Taken together, CB/DAH-HA hydrogels might be successfully exploited as a 3D artificial extracellular matrix for various tissue engineering applications.
Preparation and characterization of poly(vinyl alcohol) hydrogel based three-dimensional dosimeter for radiotherapy.
Department of Chemical Engineering and Technology, School of Environmental and Chemical Engineering, Shanghai University, Baoshan, Shanghai 200444, China.
Jong-Ho Kim, Sang Mun Bae, Moon-Hee Na, Hyeri Shin, Yu Jin Yang, Kyung Hyun Min, Ki Young Choi, Kwangmeyung Kim, Rang-Woon Park, Ick Chan Kwon, Byung-Heon Lee, Allan S Hoffman, In-San Kim
Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, 101 Dongin 2Ga, Jung-Gu, Daegu 700-422, South Korea.
Macromolecular nanoparticles can extravasate and accumulate within tumor tissues via the passive targeting system, reflecting enhanced permeability and the retention effect. However, the unsatisfactory tumor therapeutic efficacy of the passive-targeting system, attributable to the retention of extravasated nanoparticles in the vicinity of tumor vessels, argues that a new system that facilitates intracellular delivery of nanoparticles within tumors is needed. Here, we developed hydrophobically modified glycol chitosan (HGC) nanoparticles conjugated with interleukin-4 receptor (IL-4R) binding peptides, termed I4R, and tested them in mice bearing IL-4R-positive tumors. These HGC-I4R nanoparticles exhibited enhanced IL-4R-dependent cellular uptake in tumors compared to nonconjugated nanoparticles, leading to better therapeutic and imaging efficacy. We conclude that I4R facilitates and enhances cellular uptake of nanoparticles in tumor tissues. This study suggests that the intracelluar uptake of nanoparticles in tumors is an essential factor to consider in designing nanoparticles for tumor-targeted drug delivery and imaging.
Kai Wang, Moon-Hee Na, Allan S Hoffman, Gayong Shim, Su-Eun Han, Yu-Kyoung Oh, Ick Chan Kwon, In-San Kim, Byung-Heon Lee
Department of Biochemistry and Cell Biology, Cell & Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, South Korea.
When tumor cells undergo apoptosis in response to chemotherapy, the levels of apoptotic biomarkers such as histone H1 are increased at the tumor. This would amplify in situ homing signals and thus drug delivery by apoptosis-targeted drugs. To examine this possibility, we prepared apoptosis-targeted liposomes containing doxorubicin by labeling them with the CQRPPR peptide (ApoPep-1) that recognizes apoptotic cells by binding to histone H1. ApoPep-1-labeled liposomes, but not folate-labeled liposomes, inhibited tumor growth in mice more efficiently than untargeted liposomes, although in vitro cytotoxicities of those liposomes were similar. Fluorescence imaging signals at tumor were increased by the homing of ApoPep-1-labeled, fluorescent liposomes, which was correlated with the increase of apoptosis and the amount of doxorubicin at the tumor and, conversely, with the decrease of tumor volume. These results demonstrate that the apoptosis-targeted drug delivery enables in situ dose amplification and, when combined with imaging of apoptosis, provides a real-time monitoring of treatment response for cancer theragnosis.
J Control Release. 2011 Jun 15;: 21699931
RAFT-synthesized graft copolymers that enhance pH-dependent membrane destabilization and protein circulation times.
Center for Intracellular Delivery of Biologics, Department of Bioengineering, University of Washington, Seattle WA 98195, USA.
Here we describe a new graft copolymer architecture of poly(propylacrylic acid)(polyPAA) that displays potent pH-dependent, membrane-destabilizing activity and in addition is shown to enhance protein blood circulation kinetics. PolyPAA containing a single telechelic alkyne functionality was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization with an alkyne-functional chain transfer agent (CTA) and coupled to RAFT polymerized poly(azidopropyl methacrylate)(polyAPMA) through azide-alkyne [3+2] Huisgen cycloaddition. The graft copolymers become membrane destabilizing at endosomal pH values and are active at significantly lower concentrations than the linear polyPAA. A biotin terminated polyPAA graft copolymer was prepared by grafting PAA onto polyAPMA polymerized with a biotin functional RAFT CTA. The blood circulation time and biodistribution of tritium labeled avidin conjugated to the polyPAA graft copolymer was characterized along with a clinically utilized 40kDa branched polyethylene glycol (PEG) also possessing biotin functionalization. The linear and graft polyPAA increase the area under the curve (AUC) over avidin alone by 9 and 12 times, respectively. Furthermore, polyPAA graft copolymer conjugates accumulated in tumor tissue significantly more than the linear polyPAA and the branched PEG conjugates. The collective data presented in this report indicate that the polyPAA graft copolymers exhibit robust pH-dependent membrane-destabilizing activity, low cytotoxicity, significantly enhanced blood circulation time, and increased tumor accumulation.
Bioconjug Chem. 2011 Jun 13;: 21668012
Professor Tae Gwan Park (1957 - 2011) was an outstanding, innovative biomaterial scientist, and was highly admired and respected around the world. He was personally a warm-hearted, exceptionally honest, and modest person. His profound intellectual curiosity and his strong desire for excellence in research inspired many of his colleagues, his students, and his post-docs. He will be deeply missed by many people around the world.
Department of Bioengineering, University of Washington, Box 355061, Seattle, WA.
A key challenge in developing protein therapeutics or imaging agents that work against cytosolic targets is the intracellular delivery barrier. Here, we show that the pH-responsive, membrane-destabilizing polymer, poly (propylacrylic acid)(PPAA), can strongly enhance target cell killing through the intracellular delivery of a functional proapoptotic peptide. The Bak BH3 peptide induces apoptosis via antagonization of suppressor targets such as Bcl-2 and Bcl-x(L). A genetically-engineered streptavidin that contains an N-terminal TAT peptide sequence was used to optimize the pinocytotic cell uptake of biotinylated BH3 peptide and end-biotinylated PPAA. Fluorescence microscopic analysis of DAPI-stained HELA cells was used to quantitate apoptosis. Approximately 30% of cells treated with TAT-SA:BH3 complexes revealed morphologically distinct nuclear condensation, a hallmark of apoptosis. The incorporation of biotinylated PPAA had the effect of markedly enhancing the killing effect of BH3 peptides by an additional 55%(p<0.001) to a total cell killing efficiency of 85%. Caspase-3 activity was up-regulated in a TAT-SA:BH3:PPAA dose-dependent manner. The induction of apoptosis with the TAT-SA:BH3:PPAA complex was abrogated with the L78A BH3 peptide, that had been previously shown to knock-out antagonization activity. The caspase and L78A peptide results demonstrate that the delivered BH3 is indeed working through the biologically relevant apoptosis signaling pathway. These studies establish the ability of PPAA to strongly enhance the intracellular delivery of a functional pro-apoptotic peptide. Together with the PPAA, the TAT-SA adaptor complex could prove useful as a carrier of peptide/protein cargo to cultured cells.
Xiaofeng He, Moon-Hee Na, Jin-Sook Kim, Ga-Young Lee, Jae Yong Park, Allan S Hoffman, Ju-Ock Nam, Su-Eun Han, Ga Yong Sim, Yu-Kyoung Oh, In-San Kim, Byung-Heon Lee
Department of Biochemistry and Cell Biology and Cell & Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-421, Korea.
Targeted delivery of imaging agents and therapeutics to tumors would provide early detection and increased therapeutic efficacy against cancer. Here we have screened a phage-displayed peptide library to identify peptides that selectively bind to lung tumor cells. Evaluation of individual phage clones after screening revealed that a phage clone displaying the CSNIDARAC peptide bound to H460 lung tumor cells at higher extent than other phage clones. The synthetic CSNIDARAC peptide strongly bound to H460 cells and was efficiently internalized into the cells, while little binding of a control peptide was seen. It also preferentially bound to other lung tumor cell lines as compared to cells of different tumor types. In vivo imaging of lung tumor was achieved by homing of fluorescence dye-labeled CSNIDARAC peptide to the tumor after intravenous injection into mice. Ex vivo imaging and microscopic analysis of isolated organs further demonstrated the targeting of CSNIDARAC peptide to tumor. The CSNIDARAC peptide-targeted and doxorubicin-loaded liposomes inhibited the tumor growth more efficiently than untargeted liposomes or free doxorubicin. In vivo imaging of fluorescence dye-labeled liposomes demonstrated selective homing of the CSNIDARAC-liposomes to tumor. In the same context, higher levels of doxorubicin and apoptosis in tumor tissue were observed when treated with the targeted liposomes than untargeted liposomes or free doxorubicin. These results suggest that the CSNIDARAC peptide is a promising targeting probe that is able to direct imaging agents and therapeutics to lung tumor.
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Engineering nanoscopic hydrogels via photo-crosslinking salt-induced polymer assembly for targeted drug delivery.
Department of Polymer Science and Engineering and CAS Key Laboratory of Soft Matter Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
We report the preparation of biodegradable nanoscopic hydrogels and their application for targeted drug delivery. The nanogel is synthesized in a template-free method by photo-crosslinking salt-induced polymer assemblies. With convenient incorporation of targeted lactosyl moieties, the nanogels efficiently deliver doxorubicin to HepG2 cells through receptor-mediated internalization.
Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Kohoku-ku, Yokohama 223-8522, Japan.
This communication reports the synthesis, chemiluminescence properties, and biological application of KEIO-BODIPY-imidazopyrazine (KBI), a yellow-green chemiluminescent probe for the detection of reactive oxygen species (ROS) generated from living cells.
Department of Rheumatology and Physical Medicine, Erasme University Hospital,(Hôpital Erasme) Université Libre de Bruxelles, 808 Route de Lennik, 1070 Bruxelles, Belgium.
This review article describes bone remodeling in the context of osteonecrosis as a bone disease, the use of stem cells in bone and vascular diseases, and cellular therapy in osteonecrosis.
University of Maryland School of Medicine, Baltimore, MD, USA.
A systematic review of current literature for telemedicine applications that use a mobile phone was performed in MEDLINE using the following keywords: mobile phone, cell phone, and cellular phone. 23 of 994 articles were selected for their use of a mobile phone in a disease management telemedicine application. The feasibility of mobile phone based telemedicine applications is mostly supported by the literature review.
Eun Jeong Kim, Hee-Young Shin, Sangjin Park, Daekyung Sung, Sangyong Jon, Srinivasa-Gopalan Sampathkumar, Kevin J Yarema, Sung-Yool Choi, Kyuwon Kim
Division of Metrology for Quality Life, Korea Research Institute of Standards and Science, Daejeon, 305-600, Korea.
Here we report the synthesis of a novel electrochemically active polymer, preparation of adlayers of the polymer on optically transparent electrodes, and an application of the adlayers to immobilization of engineered cells through a direct covalent coupling reaction.
Beijing National Laboratory for Molecular Sciences, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China.
We report a foaming-polymerization method to prepare stable polyaniline (PANI)/polyvinyl alcohol (PVA) foams. The formation mechanism of the foam materials is investigated and the photoelectric conversion properties of PANI/PVA foams are studied in detail. The enhancement of photoelectric conversion behavior in foams is achieved, which has potential application in solar cells and nano-electronics devices.
Fabrice Bailly, Clémence Queffélec, Gladys Mbemba, Jean-François Mouscadet, Nicole Pommery, Jean Pommery, Jean-Pierre Hénichart, Philippe Cotelle
A series of thirteen 4,5-diaryl-3-hydroxy-2(5H)-furanones were synthesized. They were evaluated for their antioxidant potencies and inhibitory properties of 5-lipoxygenase, cyclooxygenases, HIV-1 integrase and PC3 cell proliferation. New hits were discovered either in the antiproliferation test or in the HIV anti-integrase test.
Using Congo red to report intracellular hydrogelation resulted from self-assembly of small molecules.
Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China.
This communication reports the use of Congo red to stain the nanofibers of self-assembled small molecules for assaying intracellular supramolecular hydrogels, which provides a convenient method to explore molecular self-assembly inside cells.
Gene Center and Department for Chemistry and Biochemistry, University of Munich, Feodor-Lynen-Strasse 25, D-81377 Munich, Germany. email@example.com
Katedra i Zakład Histologii i Embriologii, Centrum Biostruktury, Akademia Medyczna, Warszawa. firstname.lastname@example.org
In older individuals the regeneration of bone tissue is delayed due to the diminished activity of osteoblasts, while osteogenic potency of human bone marrow stromal cells, also capable of forming bone, does not change with age. The number of osteoprogenitor cells is not reduced in ageing subjects, but their proliferating rate and the activity of their derivatives--osteoblasts, is markedly diminished, since the self-renewing potential of these cells is hindered. The senescence of osteoblasts in ageing people is also accelerated. Changes within the bone marrow microenvironment reduce osteogenic potential of osteoprogenitor cells leading to impaired bone formation seen in senility, while the potency for ectopic osteogenesis does not change with age. This review summarizes documented mechanisms of changes in osteogenic activity of cells in elderly.