This compendium focuses on functionalised sugar amino acids (SAAs) and their 3- to 6-membered nitrogen heterocyclic and carbocyclic analogues. The main benefit of using SAAs and their related nitrogen and carbon congeners in the production of peptidomimetics and glycomimetics is that their properties can be readily altered via modification of their ring size, chemical manipulation of their numerous functional groups and fine-tuning of the stereochemical arrangement of their ring substituents. These building blocks provide access to hydrophilic and hydrophobic peptide isosteres whose physical properties allow entry to a region of chemotherapeutic space which is still under-explored by medicinal chemists. These building blocks are also important in providing amino acids whose inherent conformational bias leads to predisposition to secondary structure upon oligomerisation in relatively short sequences. These foldamers, particularly those containing ω-amino acids, provide an additional opportunity to expand access to the control of structures by artificial peptides. The synthesis and biological evaluation of these building blocks in glycomimetics and peptidomimetics systems keep expanding the reach of the glycosciences to the medical sciences, provide a greater outlook onto the wide range of cellular functions of saccharides and their derivatives involved and greater insight into the nature of oligosaccharide and protein folding.

https://link.springer.com/content/pdf/10.1007%2Fs00726-013-1521-1.pdf

A compendium of cyclic sugar amino acids and their carbocyclic and heterocyclic nitrogen analogues

Glaucoma is the second cause of blindness worldwide. Frequent administration of traditional topical dosage forms may lead to patient incompliance and failure of treatment. Our study aims to formula...

Sustained ocular delivery of Dorzolamide-HCl via proniosomal gel formulation: in-vitro characterization, statistical optimization, and in-vivo pharmacodynamic evaluation in rabbits.

Brain targeted rivastigmine mucoadhesive thermosensitive In situ gel: Optimization, in vitro evaluation, radiolabeling, in vivo pharmacokinetics and biodistribution

Brimonidine tartrate (BRT) is a hydrophilic α2 adrenergic agonist used for the treatment of glaucoma. Glaucoma is an ocular disease affecting the anterior segment of the eye requiring lifetime trea...

Proniosomal gel-derived niosomes: an approach to sustain and improve the ocular delivery of brimonidine tartrate; formulation, in-vitro characterization, and in-vivo pharmacodynamic study

Formulation and evaluation of cubosomes drug delivery system for treatment of glaucoma: Ex-vivo permeation and in-vivo pharmacodynamic study

Haloperidol (Hal) is one of the widely used antipsychotic drugs. When orally administered, it suffers from low bioavailability due to hepatic first pass metabolism. This study aimed at developing Hal-loaded penetration enhancer-containing spanlastics (PECSs) to increase transdermal permeation of Hal with sustained release. PECSs were successfully prepared using ethanol injection method showing reasonable values of percentage entrapment efficiency, particle size, polydispersity index and zeta potential. The statistical analysis of the ex vivo permeation parameters led to the choice of F1L – made of Span® 60 and Tween® 80 at the weight ratio of 4:1 along with 1% w/v Labrasol® – as the selected formula (SF). SF was formulated into a hydrogel by using 2.5% w/v of HPMC K4M. The hydrogel exhibited good in vitro characteristics. Also, it retained its physical and chemical stability for one month in the refrigerator. The radiolabeling of SF showed a maximum yield by mixing of 100 µl of diluted formula wit...

Penetration enhancer-containing spanlastics (PECSs) for transdermal delivery of haloperidol: in vitro characterization, ex vivo permeation and in vivo biodistribution studies.

Laser-responsive liposome for selective tumor targeting of nitazoxanide nanoparticles.

Despite of high in vitro anticancer efficacy of many chemotherapeutics, their in vivo use is limited due to lack of biocompatibility and tumor targeting. Near-infrared (NIR) photothermally induced phase transition of PLGA-PEG regime was utilized for developing highly efficient photoresponsive drug delivery systems. Co-encapsulation of plasmonic gold nanorods (GNRs), as NIR-trigger, with the novel and highly efficient anticancer drug N′-(2-Methoxybenzylidene)-3-methyl-1-phenyl-H-Thieno[2,3-c]Pyrazole-5-Carbohyd-razide (MTPC) produced NIR-responsive biodegradable polymeric (PLGA-b-PEG) nanocapsules. This remotely controllable drug release significantly enhanced both biodistribution and pharmacokinetics of the hydrophobic drug. Intravenous (IV) injection of the prepared nanocapsules (MTPC/GNRs@PLGA-PEG) to tumor-bearing mice followed by extracorporeal exposure of the tumor to NIR light resulted in highly selective drug accumulation at the tumor sites. In vivo biodistribution and pharmacokinetics utilizing iodine-131 drug-radiolabelling technique revealed a maximum target to non-target ratio (T/NT) of 5.8, 4 h post-injection with maximum drug level in the tumor (6.3 ± 0.6% of the injected dose).

Gold nanorod–loaded (PLGA-PEG) nanocapsules as near-infrared controlled release model of anticancer therapeutics

Abstract Cladribine, a purine analogue antimetabolite, was radioiodinated with 125I via direct electrophilic substitution reaction. The maximum radiochemical yield (92.5 ± 0.8%) was obtained when the reaction was done at ambient temperature for 30 min using 100 μg of Cladribine and 10 μg N-chlorosuccinamide (NCS) in 150 μL of 0.2 M phosphate buffer, pH 7. In vitro stability studies of HPLC purified 125I-Cladribine sample dissolved in 0.5 ml of 0.2 M phosphate buffer pH 7 at ambient temperature showed that 125I-Cladribine is stable up to 12 h post labeling. Biodistribution results revealed excretion of 125I-Cladribine mainly by kidneys. The uptake of 125I-Cladribine in the induced Ehrlich Ascites Carcinoma was 2.8 ± 0.4 %ID/g at 1 h post injection with maximum tumor/muscle ratio of 5.5. The good uptake of 125I-Cladribine confirms the molecular docking studies results which indicate that iodinated Cladribine binds with polymerase enzyme with a good –CDOCKER energy. As a result, radioiodinated Cladribine may be used as a valuable agent for tumor diagnosis and therapy.

Radioiodination and biological evaluation of Cladribine as potential agent for tumor imaging and therapy

Despite the high in vitro efficacy of photodynamic therapeutics, lack of tumor targeting significantly reduces their in vivo efficacy and thus limits their clinical use. Photoimmunotherapy (PIT) is a new synthetic strategy to target and treat cancer by photodynamic therapy (PDT). In this study, we describe design and synthesis of a third-generation photosensitizer comprising a PEGylated-phthalocyanine star-polymer photosensitizer that covalently bound to a myeloma tumor-selective antibody (MAb) via the carbodiimide chemistry. The free photosensitizer demonstrated a minimum dark toxicity when tested in mammalian myeloma cell line (SP2/OR); and a moderate phototoxicity after irradiation with non thermal laser red light as a result of light-induced production of cytotoxic singlet oxygen species. Covalent attachment of the photosensitizer (Pc) to the MAb resulted in a significantly enhanced phototoxicity. This is mainly ascribed to the fact that internalization enhances phototoxicity of Pc-MAb bioconjugates. The radioactivated photoimmuno-conjugates 131I(PcMAb) demonstrated the highest phototoxicity to myeloma cells. The suggested bioconjugates are promising candidates as multiple therapeutic models for in vivo treatment of myeloma.

Noha A. Bayoumi

Papers

Penetration enhancer-containing spanlastics (PECSs) for transdermal delivery of haloperidol: in vitro characterization, ex vivo permeation and in vivo biodistribution studies.

Laser-responsive liposome for selective tumor targeting of nitazoxanide nanoparticles.

Gold nanorod–loaded (PLGA-PEG) nanocapsules as near-infrared controlled release model of anticancer therapeutics

Radioiodination and biological evaluation of Cladribine as potential agent for tumor imaging and therapy

Targeted photoimmunotherapy based on photosensitizer-antibody conjugates for multiple myeloma treatment.