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Targeted Delivery Systems Based on Polymeric Nanoparticles for Biomedical Applications
Published in Anil K. Sharma, Raj K. Keservani, Rajesh K. Kesharwani, Nanobiomaterials, 2018
Sa Yang, Can Huang, Zhi-Ping Li, Qian Ning, Wen Huang, Wen-Qin Wang, Cui-Yun Yu
Somatostatin receptors (SSTRs) are members of the superfamily of G-protein-coupled receptors (GPCR), which are widely distributed in a variety of tumors and cancer cell lines, including small cell lung cancer, neuroendocrine tumors, prostate cancer, breast cancer, colorectal carcinoma, gastric cancer and hepatocellular carcinoma. SSTRs have high affinity with somatostatin and somatostatin analogues (Schonbrunn et al., 1978; Stengel et al., 2013). This has led to two clinical applications. First, somatostatin analogues, such as octreotide or lanreotide, can functionally inhibit the excess hormone release and the further growth of these tumors. Second, radiolabeled somatostatin analogues can be used for diagnostic imaging of the tumors and targeted radiotherapy (Oberg et al., 2010; Waser et al., 2012). To date five SSTR subtypes have been cloned (SSTR1-SSTR5). The receptor genes are intron-less except for a SSTR2 intron that produces 2 spliced variants, SSTR2a and SSTR2b. Many tumor cells most frequently express SSTR2 at a high concentration, some also express SSTR1, 3, and 5, but fewer express SSTR4 (Sun et al., 2011; Froidevaux et al., 2002). In some reports, SSTR2 is upregulated in proliferative endothelial cells (ECs) lining the internal wall of tumor blood vessels, but undetectable in quiescent ECs (Reubi et al., 1996; Watson et al., 2001). Due to the aberrant expression in tumors and tumoral blood vessels, these SSTRs, specifically SSTR2, have been considered for ligand-based targeted therapy.
Arsenals of Pharmacotherapeutically Active Proteins and Peptides: Old Wine in a New Bottle
Published in Debarshi Kar Mahapatra, Swati Gokul Talele, Tatiana G. Volova, A. K. Haghi, Biologically Active Natural Products, 2020
The excessive synthesis of ST results in a condition called acromegaly. The major reasons behind the excessive synthesis of ST are somatotroph adenomas of the pituitary gland. The acromegaly can be treated by removing the adenomas surgically followed by radiation therapy and administering drugs. Somatostatin analogs like octreotide are used for the inhibition of growth hormone synthesis. These analogs also inhibit the secretion of insulin, glucagon, and several GI hormones and trigger cholelithiasis. Pegvisomant is a recombinant hGH analog which has an ST receptor antagonist [134].
The emergence of nanoporous materials in lung cancer therapy
Published in Science and Technology of Advanced Materials, 2022
Deepika Radhakrishnan, Shan Mohanan, Goeun Choi, Jin-Ho Choy, Steffi Tiburcius, Hoang Trung Trinh, Shankar Bolan, Nikki Verrills, Pradeep Tanwar, Ajay Karakoti, Ajayan Vinu
Tumour site penetration with the drug delivery carrier system is the most problematic task, especially in relation to organic nanoparticles. Administration of liposomes was explored by immobilizing the drug triptolide (diterpenoid epoxide) into the liposomes functionalised with dual ligands. The dual ligands functionalised on the surface were anti-carbonic anhydrase IX (anti-CA IX) and CPP33 (tumour lineage-homing cell-penetrating peptide, with a sequence of RLWMRWYSPRTRAYG). MTT assay showed that the triptolide loaded liposomes modified with dual ligands has a higher toxicity than the bare liposomes without modification. The results were confirmed in both the 2D cell lines and in 3D tumour spheroids [264]. Octreotide molecule is another targeting agent that mimics the natural somatostatin and enables the liposomes to easily bind with the surface receptors on cancer cells as well as escape the macrophage degradation. The octreotide functionalised liposomes were loaded with the drug epirubicin with an encapsulation efficiency of 97.8%. The survival rate of lung metastatised cells treated with peptide modified liposomes was reduced significantly than normal epirubicin encapsulated liposomes [265]. Cao et al. designed macrophage membrane coated and emtansine loaded liposomes with high expression of α4β1 integrin for specifically targeting the metastatised lung tumours from the breast cancer cells [266]. These macrophage membrane coated liposomes were able to bind to the overexpressed 4T1 sites on the metastasised tumour cells and specifically target the same.
Progress in spray-drying of protein pharmaceuticals: Literature analysis of trends in formulation and process attributes
Published in Drying Technology, 2021
Joana T. Pinto, Eva Faulhammer, Johanna Dieplinger, Michael Dekner, Christian Makert, Marco Nieder, Amrit Paudel
A number of endocrine hormones are polypeptides and are vital for regulating biological processes such as metabolism, reproduction, ion balance as well as development and growth.[76] Insulin was the first therapeutically approved peptide to treat Diabetes Mellitus I and was/is available as an injectable liquid formulation.[77] The approval of the spray-dried insulin for inhalation (Exubera® Pfizer) in 2006 made spray-drying of large biological molecules a palpable reality. Since then, spray-drying of many other peptide hormones such as human growth hormone,[24,78–84] octreotide acetate,[85] parathyroid hormone[86,87], salmon calcitonin,[88,89] and ceterolix-acetate[90] have been highly investigated and some have been approved (i.e. triptorelin pamoate and lanreotide acetate).
New approaches towards the discovery and evaluation of bioactive peptides from natural resources
Published in Critical Reviews in Environmental Science and Technology, 2020
Nam Joo Kang, Hyeon-Su Jin, Sung-Eun Lee, Hyun Jung Kim, Hong Koh, Dong-Woo Lee
Peptides generated by enzymatic proteolysis perform many vital functions in biological metabolism and signaling. Over 60 linear and cyclized peptides with pharmaceutical activities, such as insulin, adrenocorticotropic hormone, calcitonin, oxytocin, vasopressin, and octreotide, are currently used as anti-cancer, anti-obesity, and immunomodulatory agents (Lau & Dunn, 2018). When used over prolonged periods, however, small molecules as synthetic drugs are not free from side effects, suggesting that natural compounds and their derivatives represent safer alternatives for therapeutic applications (Dimopoulos et al., 2014). In light of this, BPs derived from natural resources such as foods and plants are ranked above small molecules in terms of biosafety (Lau & Dunn, 2018). From an industrial standpoint, natural BPs have segmented the peptide therapeutics market according to application (food vs. pharmacological), source, manufacturer, route of administration, synthesis technology, and region. In particular, the source of origin (i.e. animal vs. plant) and type of manufacturing processes (chemical vs. biological) are critical determinants of contemporary customers’ preferences in the food and pharmaceutical industries (Tucker et al., 2016).