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  • 23986-74-5 br Biotin vitamin H is an essential micronutrient


    Biotin (vitamin H) is an essential micronutrient, which is vital for normal cellular function (Livaniou et al., 2000). Owing to low mole-cular weight, relatively simple biochemical structure, and high tumor specificity, biotin has attracted great attention from pharmaceutical research. In order to thrive and multiply rapidly, cancer 23986-74-5 need extra biotin as compared to normal cells. Rapidly proliferating malignant cells overexpress biotin in order to meet their biotin uptake. Biotin overexpression is observed in wide types of cancers, including renal (RENCA, RD0995), lung (A549, M109), ovarian (OV 2008, ID8), mas-tocytoma (P815) and breast (4T1, JC, MMT06056) cancer cell lines (Shi et al., 2014). This specific interaction of biotin and its receptors has been explored to develop various biotin-conjugated nanocarriers to increase the uptake of anticancer drugs by various tumor cells (Bu et al., 2013; Minko et al., 2002; Taheri et al., 2011; Tseng et al., 2009; Vadlapudi et al., 2013; Yang et al., 2009; Yang et al., 2014; Yellepeddi et al., 2009).
    Dendrimers are hyperbranched macromolecules having mono-dispersed three-dimensional structure with specific molecular weight and available in many generations based on the layer of branches put on the core (Cheng et al., 2008; Esfand and Tomalia, 2001). Poly (amidoamine) (PAMAM) dendrimers are the first commercially used class of dendrimers for drug delivery investigations (Tomalia, 2005). In general, the dendrimers possess vacant internal pockets which can hold the poorly soluble cargoes (Jansen and Meijer, 1994). Additionally, the outer shell of dendrimers possess a wide number and variety of surface functional groups which can be conjugated or anchored with various moieties (Majoros et al., 2006; Thomas et al., 2005). PAMAM den-drimers have been widely explored for delivery of poorly soluble anti-cancer agents to specific target sites (Asthana et al., 2005; Bhadra et al., 2005; Bhadra et al., 2003; D'emanuele et al., 2004; Milhem et al., 2000; Najlah et al., 2006, 2007). Further, PAMAM dendrimers find applica-tion in gene delivery with specificity to cancer cells (Li et al., 2018; Liu et al., 2017). Ease of fabrication, nanometer size, biocompatibility, scalability are some of the advantages that make dendrimers a potential drug delivery system (Duncan and Izzo, 2005; Svenson and Tomalia, 2012). Previous studies reported the active targeting of dendrimers by conjugation of ligands such as folic acid (Thomas et al., 2005), biotin (Xu et al., 2007; Yellepeddi et al., 2009), Lactobionic acid (Iacobazzi et al., 2017), antibodies (Patri et al., 2004), peptides (Shukla et al., 2005), and epidermal growth factor (Barth et al., 2004) to dendrimers thereby enhancing the therapeutic potential of cancer chemother-apeutics.
    In the present study, we have developed and investigated the po-tential of biotin conjugated PEGylated multifunctional PAMAM den-drimer system to effectively deliver paclitaxel 23986-74-5 (PTX), a chemother-apeutic agent which suffers poor physicochemical properties. The unique globular structure of PAMAM dendrimers allows the spatial arrangement of biotin molecules on the surface which might contribute to superior internalization of the delivery system into the cancer cells (Yellepeddi et al., 2009). Following the synthesis, we have character-ized the conjugates and evaluated the delivery system in biotin over-expressed human lung cancer cell line (A549). A 3D tumor spheroid model which mimics in vivo tumor has been employed to evaluate the uptake and therapeutic potential of the developed dendrimer system.  International Journal of Pharmaceutics 557 (2019) 329–341
    2. Materials and methods
    Poly(amidoamine) dendrimer of ethylenediamine core and genera-tion 4.0 with 64 terminal amino groups (G4 PAMAM) was procured from Dendritech (USA). A gratis sample of Paclitaxel (PTX) was re-ceived from Fresenius Kabi India Pvt., Ltd. (Gurgaon, India). Methoxy-polyethyleneglycol-succinimidyl carboxymethyl ester of molecular weight 2000 Da (mPEG-SCM ester) was purchased from Jenkem Technology (USA). N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC. HCl, 98%), Biotin and N-Hydroxysuccinimide (NHS, 98%) were procured from Sigma Aldrich Chemicals (USA). Regenerated cellulose dialysis membrane of molecular weight cut-off 2 kDa, 3.5 kDa and 14 kDa was purchased from Spectrum Laboratories, Inc. (USA). N-ethyldiisopropylamine (DIPEA), NHS-Fluorescein was purchased from Avra Chemicals (India), and Thermo Scientific (USA) respectively. N,N'-Dicyclohexylcarbodiimide (DCC) was purchased from Spectrochem Chemicals Ltd. (India). The solvents and reagents utilized in the study were of analytical grade.