Selective and targeted delivery of drugs to tumors is a major challenge for an effective cancer therapy and also to overcome the side-effects associated with current treatments. Overexpression of various receptors on tumor cells is a characteristic structural and biochemical aspect of tumors and distinguishes them from physiologically normal cells. This abnormal feature is therefore suitable for selectively directing anticancer molecules to tumors by using ligands that can preferentially recognize such receptors. Several subtypes of integrin receptors that are crucial for cell adhesion, cell signaling, cell viability, and motility have been shown to have an upregulated expression on cancer cells. Thus, ligands that recognize specific integrin subtypes represent excellent candidates to be conjugated to drugs or drug carrier systems and be targeted to tumors. In this regard, integrins recognizing the RGD cell adhesive sequence have been extensively targeted for tumor-specific drug delivery. Here we review key recent examples on the presentation of RGD-based integrin ligands by means of distinct drug-delivery systems, and discuss the prospects of such therapies to specifically target tumor cells.

Integrins have been proven to be valuable therapeutic targets in the treatment of several inflammatory and autoimmune diseases, where leukocyte adhesion processes are regulated by them. Furthermore, they play an important role in pathological angiogenesis and tumor metastasis, being a promising target for cancer therapy.

By the end of the twentieth century, the interest in natural compounds as probable sources of drugs has declined and was replaced by other strategies such as molecular target-based drug discovery. However, in the recent times, natural compounds regained their position as extremely important source drug leads. Indole-containing compounds are under clinical use which includes vinblastine and vincristine (anticancer), atevirdine (anti-HIV), yohimbine (erectile dysfunction), reserpine (antihypertension), ajmalicine (vascular disorders), ajmaline (anti-arrhythmic), vincamine (vasodilator), etc. Monoterpene Indole Alkaloids (MIAs) deserve the curiosity and attention of researchers due to their chemical diversity and biological activities. These compounds were considered as an impending source of drug-lead. In this review 444 compounds, were identified from six genera belonging to the family Apocynaceae, will be discussed. These genera (Alstonia, Rauvolfia, Kopsia, Ervatamia, and Tabernaemontana, and Rhazya) consist of 400 members and represent 20% of Apocynaceae species. Only 30 (7.5%) species were investigated, whereas the rest are promising to be investigated. Eleven bioactivities, including antibacterial, antifungal, anti-inflammatory and immunosuppressant activities, were reported. Whereas cytotoxic effect represents 47% of the reported activities. Convincingly, the genera selected in this review are a wealthy source for future anticancer drug lead.

We present a click chemistry-based molecular toolkit for the biofunctionalization of materials to selectively control integrin-mediated cell adhesion. To this end, α5β1-selective RGD peptidomimetics were covalently immobilized on Ti-based materials, and the capacity to promote the selective binding of α5β1 was evaluated using a solid-phase integrin binding assay. This functionalization strategy yielded surfaces with a nine-fold increased affinity for α5β1, in comparison to control samples, and total selectivity against the binding of the closely related integrin αvβ3. Moreover, our methodology allowed the screening of several phosphonic acid containing anchoring units to find the best spacer-anchor moiety required for establishing an efficient binding to titanium and to promote selective integrin binding. The integrin subtype specificity of these biofunctionalized surfaces was further examined in vitro by inducing selective adhesion of genetically modified fibroblasts, which express exclusively the α5β1 integrin. The versatility of our molecular toolkit was proven by shifting the cellular specificity of the materials from α5β1- to αvβ3-expressing fibroblasts by using an αvβ3-selective peptidomimetic as coating molecule. The results shown here represent the first functionalization of Ti-based materials with α5β1- or αvβ3-selective peptidomimetics that allow an unprecedented control to discriminate between α5β1- and αvβ3-mediated adhesions. The role of these two integrins in different biological events is still a matter of debate and is frequently discussed in literature. Thus, such bioactive titanium surfaces will be of great relevance for the study of integrin-mediated cell adhesion and the development of new biomaterials targeting specific cell types.

Poly(ethylene glycol) micropillars with gold nanopatterns on top are functionalized with two integrin selective ligands. This platform is a powerful new tool to determine the specific contribution of traction forces involved in cell adhesion mediated by α5 β1‐ and αvβ3‐ integrins. Cells adherent via α5 β1‐integrins have a tendency to exert higher maximum forces than cells adhering via αvβ3‐integrins.

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A simple, economically viable and fast method has been utilized for the preparation of highly active metal nanoparticles (MNPs) in coating layer of chitosan (CH) over cellulose microfibers of cotton cloth (CC). 2 wt% of CH solution was used for the coating of CC strips (CC-CH), and were kept in aqueous solutions of metal salts to adsorb metal ions. The CC-CH templated with metal ions were then treated with aqueous solution of NaBH4 to reduce the metal ions into zero-valent metal nanoparticles (M0). The CC-CH strips loaded with M0 were characterized by XRD, XPS, ATR-FTIR, FE-SEM and TGA, which indicates the successful synthesis of MNPs by this method. The M0/CC-CH strips were used as an efficient catalyst for the model reduction reaction of nitrophenol and toxic organic dyes. Among all the prepaped samples, Fe/CC-CH showed good catalytic activity for 4-NP and Rh-B dye reduction in the presence of NaBH4 with rate constants of 0.2937 min−1 and 0.3804 min−1, respectively. Moreover Fe/CC-CH has good catalytic reduction ability for MO and MB having rate constants equal to 0.1698 and 0.2802 min−1, respectively. Beside the good catalytic ability, it could be easily recoverable as compared to other available techniques. The recovery was completed by simply pulling the strip from the reaction matrix after completion of the reaction and can be used several times.

Species of the marine red algae Laurencia, are known to exhibit bromine and chlorine-containing C 15 nonterpenoid metabolites.1) Among these, are the unusual cyclic ethers, with a pentadec-3-en-1-yne carbon skeleton. The isolation of trans and cis-laurediols from L. nipponica indicated an evidence that, cyclic ether enynes were raised from linear C 15 acetylenic polyenes, through oxidation and cyclization processes.2) Several maneonenes (halogenated cyclic ether enyne) were isolated from the genus Laurencia, 3-9) the fundamental differences between them is either geometry (through C 3 -C 4 and/or C 12 -C 13 ) and/or stereochemical configuration (C 5 , C 6 and C 11 ).Apoptosis is a programmed form of cell death by which unwanted cells are removed from the body without causing inflammation.10) This contrasts with necrosis, which involves direct damage to cells and is associated with inflammation. 11)Apoptosis may be an alternative and better method by which cells, such as neutrophils, are removed from an inflamed site.12) An organism must also remove senescent, damaged, or abnormal cells that could interfere with organ function or develop into tumors.In the present investigations, we describe the isolation and structural elucidation of three new (cyclic ether enynes) 1, 2 and 3 along with one known isomer 4 5-7) obtained from the petroleum ether extract of the red alga L. obtusa. Results and DiscussionThe petroleum ether extract of the air dried algal material was fractionated on aluminum oxide column using a stepped gradient of hexane and ether. The fractions were examined by spot TLC chromatography and spray reagent methanolsulfuric acid (50%) to give four compounds (1-4).The spectral data of these four compounds (Table 1) showed their very close structural relationship and strongly suggested that they belong to the C 15 acetogenins. The structure of known (12E)-cis-maneonene-A (4) was established by comparing its physical and spectral data with literature. 5-7)Compound 1, was isolated as pale yellow oil. High resolution-electron ionization-mass spectra (HR-EI-MS) established the molecular formula C 15 H 16 BrClO 2 , implying 7 degrees of unsaturation. EI-MS exhibited a characteristic molecular-ion cluster at m/z 342/344/346 in a ratio 2 : 3 : 1, which clearly indicated the presence of one Br and one Cl atoms. The presence of acetylenic group, vinyl ether stretching, and two C-O functionalities were deduced from IR absorptions at n max 3286, 1687, 1126, and 1190 cm Ϫ1 , respectively. Hence, both oxygen atoms could be involved in ether links. The 13 C-NMR and distortionless enhancement by polarization transfer (DEPT) experiments allowed the determination of 1 methyl, 2 methylene, 9 methine and 3 quaternary carbon atoms. Moreover, 13 C-NMR and heteronuclear single quantum coherence (HSQC) spectra displayed resonance for four carbons bearing oxygen, three of these were demonstrated by the signals at d C 78.2, 79.4, and 82.9; while the fourth is of vinyl ether carbon at d C 152.0.The presence of a terminal conjugate...