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The development of enhanced drug delivery systems is one of the most attractive fields of pharmaceutical sciences, as some of the highly effective chemo/biotherapeutics for cancer treatment can not be administrated due to their high toxicities for normal cells or low stability in physiological media. However, drugs that are currently not administrable will become valuable if specific cell-targeted drug carriers can protect the normal cells from adverse effects and also improve drug pharmacokinetics. Aptamers are attractive and promising biomaterials developed with high affinity and specificity against numerous valuable targets. They could act similar to monoclonal antibodies (mAbs), and offer significant advantages. Combined with aptamers, nanostructures are smart veicles with remarkable properties for drug delivery. Combination of aptamer and nanotechnology has resulted in the production of various targeted drug delivery systems which are highly efficient in therapeutic and diagnostic applications. In this review, some of the efforts related to design and development of aptamer-targeted nanocarriers have been summarized considering: i) Aptamer importance as smart ligands and the aptamer development methods ii) Types of nanostructures combined with aptamers as targeting agent proposed in the literature iii) Cancer specific aptamers evaluated in combination with nanocarriers for diagnostic and therapeutic applications and iv) Discussion of aptamer-based smart nanocarriers according to the trend of related research works. [ABSTRACT FROM AUTHOR]

A quantitative structure activity relationship analysis has been applied to a data set of 20 N-phenyl-N′-(4-pyridinyl)-urea derivatives with anticonvulsant activity. Semi-empirical quantum chemical calculations at AM1 level was used to find the optimum 3D geometry of the studied molecules. Four types of molecular descriptors including classical (substituent constants), constitutional, topological and quantum chemical was used to derive a quantitative relationship between the anticonvulsant activity and structural properties. A multi-parametric equation containing three descriptors with good statistical qualities was obtained using multiple linear regression (MLR). In addition, partial least squares (PLS) regression was used to model the structure-activity relationships, more accurately. The results confirmed the superiority of the results obtained by PLS relative to MLR. The respective percent relative errors of prediction for the MLR and PLS regression methods was between (-3.18)–(+3.15) and (-1.28)–(+1.52). [Copyright &y& Elsevier]

Peptides are oligomers of amino acids, which have been used in a wide range of applications, particularly in medical and pharmaceutical sciences. Linear peptides have been extensively developed in various fields of medicine as therapeutics or targeting agents. The branched structure of peptide dendrimers with peptide (commonly, poly l ‑Lysine) or non-peptide (commonly poly‑amidoamine) core, often exhibits valuable novel features, improves stability and enhances the functionality of peptide in comparison with small linear peptides. The potential applications of Branched and hyper-branched peptidic structures which are known as peptide dendrimers in biomedical sciences have been approved vastly. A peptide dendrimer contains three distinct parts including core, building blocks and branching units or surface functional groups. These structures provide a lot of opportunities in the pharmaceutical field, particularly for novel drug development. In this review, a brief summary of different biomedical applications of peptide dendrimers is presented, and peptide dendrimers as active pharmaceutical ingredients and drug delivery carriers are discussed. Applications of peptide dendrimers in vaccines and diagnostic tools are also presented, in brief. Generally, peptide dendrimers are promising biomaterials with high evolution rate for clinical and non-clinical applications in medicine. Unlabelled Image [ABSTRACT FROM AUTHOR]