Monthly Archives: January 2017

PLGA from PolySciTech used as part of optimized doxorubicin nanoparticle study

Nanoparticles references formulations which are submicron in size. A great deal of expertise goes into making nanoparticles with precise properties and this is an exciting field of research for a wide variety of treatments. Recently, researchers utilized PLGA (PolyVivo AP082) from PolySciTech (www.polyscitech.com) for formulation optimization of doxorubicin loaded particles. This research holds promised for improved chemotherapy strategies. Read more: Shaikh, Muhammad Vaseem, Manika Kala, and Manish Nivsarkar. “Formulation and optimization of doxorubicin loaded polymeric nanoparticles using Box-Behnken design: ex-vivo stability and in-vitro activity.” European Journal of Pharmaceutical Sciences (2017). http://www.sciencedirect.com/science/article/pii/S0928098717300507

“Abstract: Biodegradable nanoparticles (NPs) have gained tremendous interest for targeting chemotherapeutic drugs to the tumor environment. Inspite of several advances sufficient encapsulation along with the controlled release and desired size range have remained as considerable challenges. Hence, the present study examines the formulation optimization of doxorubicin loaded PLGA NPs (DOX-PLGA-NPs), prepared by single emulsion method for cancer targeting. Critical process parameters (CPP) were selected by initial screening. Later, Box-Behnken design (BBD) was used for analyzing the effect of the selected CPP on critical quality attributes (CQA) and to generate a design space. The optimized formulation was stabilized by lyophilization and was used for in-vitro drug release and in-vitro activity on A549 cell line. Moreover, colloidal stability of the NPs in the biological milieu was assessed. Amount of PLGA and PVA, oil:water ratio and sonication time were the selected independent factors for BBD. The statistical data showed that a quadratic model was fitted to the data obtained. Additionally, the lack of fit values for the models was not significant. The delivery system showed sustained release behavior over a period of 120 h and was governed by Fickian diffusion. The multipoint analysis at 24, 48 and 72 h showed gradual reduction in IC50 value of DOX-PLGA-NPs (p < 0.05, Fig. 9). DOX-PLGA-NPs were found to be stable in the biological fluids indicating their in-vivo applicability. In conclusion, optimization of the DOX-PLGA-NPs by BBD yielded in a promising drug carrier for doxorubicin that could provide a novel treatment modality for cancer.”

Oral chemotherapeutic delivery system developed using PCL from PolySciTech

Paclitaxel is a widely applicable anticancer agent which prevents cancer cells from dividing and proliferating. Currently, the only administration route for paclitaxel is by intravenous injection. For chronic applications, this can be a very invasive procedure, such as surgical placement of a PICC line in the vein of the arm or port-a-cath directly into the entrance of the heart. Clearly, an oral delivery system would be preferred in terms of patience comfort as well as management of costs and potential complications associated with catheters.  By itself, Paclitaxel has very poor uptake when administered orally. However, researchers have utilized PCL (PolyVivo AP129) from PolySciTech Division of Akina, Inc. (www.polyscitech.com) and conjugated it to chitosan to form a biocompatible micelle system which significantly enhances paclitaxel absorption. This research holds promise for less-invasive and more sustainable delivery of paclitaxel to patients. Read more: Almeida, Andreia, Daniella Silva, Virginia Gonçalves, and Bruno Sarmento. “Synthesis and characterization of chitosan-grafted-polycaprolactone micelles for modulate intestinal paclitaxel delivery.” Drug Delivery and Translational Research (2017): 1-11. http://link.springer.com/article/10.1007/s13346-017-0357-8

“Abstract: In this work, self-assembled amphiphilic micelles based on chitosan (CS) and polycaprolactone (PCL) were produced and used as carriers of paclitaxel (PTX) to improve its intestinal pharmacokinetic profile. Chitosan-grafted-polycaprolactone (CS-g-PCL) was synthesized through a carbodiimide reaction by amidation and confirmed by Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance analysis (1H NMR), and contact angle evaluation. Micelles were produced by solvent evaporation method, and the critical micelle concentration was investigated by conductimetry. The obtained micelles were of 408-nm mean particle size, narrow size distribution (polydispersity index of 0.335) and presented positive surface charge around 30 mV. The morphology of micelles assessed by transmission electron microscopy (TEM) revealed round and smooth surface, in agreement with dynamic light scattering measurements. The association efficiency determined by high-performance liquid chromatography (HPLC) was as high as 82%. The in vitro cytotoxicity of the unloaded and PTX-loaded micelles was tested against Caco-2 and HT29-MTX intestinal epithelial cells, resulting in the absence of cell toxicity for all formulations. Moreover, the permeability of PTX-loaded micelles in Caco-2 monolayer and Caco-2/HT29-MTX co-culture model was determined. Results showed that the permeability of PTX was higher in Caco-2/HT29-MTX co-culture model compared with Caco-2 monolayer due to the mucoadhesive character of micelles, acting as a platform to deliver PTX at the sites of absorption. Therefore, it can be concluded that the PTX-loaded CS-g-PCL micelles, employed for the first time as PTX carriers, may be a potential drug carrier for the intestinal delivery of hydrophobic drugs, particularly anticancer agents. Keywords: Chitosan, Polycaprolactone, Paclitaxel, Micelles, Drug delivery”

Stem-cell tissue scaffold for spinal-repair constructed using polymers from PolySciTech

An exciting application of biodegradable polymer technology is the regeneration of new tissue using an appropriate scaffold seeded with mesenchymal stem cells. Recently, researchers utilized PLGA from PolySciTech (www.polyscitech.com) (PolyVivo cat# AP045) as part of a scaffold system to support the regrowth of spinal cord tissue using stem cells. This research holds promise for potentially repairing spinal breaks as a treatment for paralysis. Read more: Ropper, Alexander E., Devang K. Thakor, InBo Han, Dou Yu, Xiang Zeng, Jamie E. Anderson, Zaid Aljuboori et al. “Defining recovery neurobiology of injured spinal cord by synthetic matrix-assisted hMSC implantation.” Proceedings of the National Academy of Sciences (2017): 201616340. http://www.pnas.org/content/early/2017/01/12/1616340114.short

“Abstract: Mesenchymal stromal stem cells (MSCs) isolated from adult tissues offer tangible potential for regenerative medicine, given their feasibility for autologous transplantation. MSC research shows encouraging results in experimental stroke, amyotrophic lateral sclerosis, and neurotrauma models. However, further translational progress has been hampered by poor MSC graft survival, jeopardizing cellular and molecular bases for neural repair in vivo. We have devised an adult human bone marrow MSC (hMSC) delivery formula by investigating molecular events involving hMSCs incorporated in a uniquely designed poly(lactic-co-glycolic) acid scaffold, a clinically safe polymer, following inflammatory exposures in a dorsal root ganglion organotypic coculture system. Also, in rat T9–T10 hemisection spinal cord injury (SCI), we demonstrated that the tailored scaffolding maintained hMSC stemness, engraftment, and led to robust motosensory improvement, neuropathic pain and tissue damage mitigation, and myelin preservation. The scaffolded nontransdifferentiated hMSCs exerted multimodal effects of neurotrophism, angiogenesis, neurogenesis, antiautoimmunity, and antiinflammation. Hindlimb locomotion was restored by reestablished integrity of submidbrain circuits of serotonergic reticulospinal innervation at lumbar levels, the propriospinal projection network, neuromuscular junction, and central pattern generator, providing a platform for investigating molecular events underlying the repair impact of nondifferentiated hMSCs. Our approach enabled investigation of recovery neurobiology components for injured adult mammalian spinal cord that are different from those involved in normal neural function. The uncovered neural circuits and their molecular and cellular targets offer a biological underpinning for development of clinical rehabilitation therapies to treat disabilities and complications of SCI. Keywords: spinal cord injury recovery, neurobiology, mesenchymal stromal stem cell, PLGA, locomotion.”

mPEG-PLLA from PolySciTech used for synthesis of photodynamic chemotherapy agent

Photodynamic therapy is a novel cancer treatment option which utilizes special agents, referred to as photosensitizers. These reagents are inactive and non-toxic under typical conditions but can be activated by certain wavelengths of light to kill cancerous cells. The benefit of such a therapy, over conventional chemotherapy, is that the location of action can be controlled by selectively illuminating the tumor region. PolySciTech division of Akina, Inc. (www.polyscitech.com) provides a wide variety of block copolymers which work well for forming micelle or nanoparticle formulations for medicinal delivery. Recently, mPEG-PLLA (PolyVivo AK004) was utilized by researchers at Wroclaw University as a precursor to synthesize zinc(II) phthalocyanine conjugate for photodynamic therapy. This research holds promise for safe and effective cancer therapy with lower side-effects. Read more: Lamch, Łukasz, Marta Tsirigotis-Maniecka, Julita Kulbacka, and Kazimiera A. Wilka. “Synthesis of new zinc (II) phthalocyanine conjugates with block copolymers for cancer therapy.” Organic Chemistry part ii (2017): 433-445. http://www.arkat-usa.org/get-file/58826/

“Abstract: Synthetic routes towards new conjugates of hydrophilic zinc(II) phthalocyanine (ZnPc) with poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (Pluronic P123) and poly(L-lactide) (PLLA), are described. The main semiproduct ZnPc was obtained by heating 4-nitrophthalimide with urea and zinc chloride, followed by the reduction step. Steglich esterification was used to synthesize two ZnPc-conjugated block copolymers, further utilized in fabrication of polymeric micelles (PMs) – functionalized with the zinc(II) phthalocyanine-type moiety. Biological evaluation of the PMs indicated an acceptable biocompatibility level in accord with requirements in the field of nanotheranostics and nanomedicine. Keywords: ZnPc-conjugated block copolymers; cyclotetramerization; Steglich esterification; fluorescent polymeric micelles; diagnostic marker; in vitro biological evaluation”

Uses for Akanocure Stereotetrad Lactones 5b: Full Lactone Reductions

One of PolySciTech’s latest product offerings is Akanocure stereotetrad lactones (https://akinainc.com/polyscitech/products/akanocure/index.php) for use as synthetic precursors. There are many potential reactions for these lactones which can result in a wide array of useful molecules. In this series of postings, we will highlight potential uses of these materials. One potential usage is the full reduction of the lactone. This reaction has been utilized in the past to provide for synthesis of (+)-neopeltolide fragments, a chemotherapeutic agent. This research holds promise for improved availability of chemotherapeutic agents. Read more: Mineeva, I. “New approach to the synthesis of macrocyclic core of cytotoxic lactone (+)-neopeltolide. Synthesis of CC segment basing on cyclopropanol intermediates.” Russian Journal of Organic Chemistry 51, no. 8 (2015). http://link.springer.com/article/10.1134/S1070428015080023

“A new retrosynthetic procedure was developed for the synthesis of the macrocyclic core of a cytotoxic lactone (+)-neopeltolide utilizing cyclopropanol intermediates. The synthesis was suggested and carried out of the C7–C16 segment of (+)-neopeltolide to obtain (4S,6S)-6-[(2S)-2-hydroxypentyl]-4-methyltetrahydro-2H-pyran-2-one. The possibility was demonstrated of a formal synthesis based on the obtained product of the potential antitumor pharmaceutical (+)-neopeltolide.”

 

Uses for Akanocure Stereotetrad Lactones 5a: Full Lactone Reductions

One of PolySciTech’s latest product offerings is Akanocure stereotetrad lactones (https://akinainc.com/polyscitech/products/akanocure/index.php) for use as synthetic precursors. There are many potential reactions for these lactones which can result in a wide array of useful molecules. In this series of postings, we will highlight potential uses of these materials. One potential usage is the full reduction of the lactone. This reaction has been utilized in the past to provide for synthesis of salinomycin, a powerful antibiotic agent which has proven itself effective against problematic bacterial such as MRSA. This research holds promise for improved antibiotics production. Read more: Yadav, J. S., Vinay K. Singh, and P. Srihari. “Formation of Substituted Tetrahydropyrans through Oxetane Ring Opening: Application to the Synthesis of C1–C17 Fragment of Salinomycin.” Organic letters 16, no. 3 (2014): 836-839. http://pubs.acs.org/doi/abs/10.1021/ol403604u?journalCode=orlef7&quickLinkVolume=16&quickLinkPage=836&selectedTab=citation&volume=16

“The stereoselective synthesis of C1–C17 fragment of salinomycin is achieved. The strategy employs a desymmetrization approach and utilizes an intramolecular oxetane opening reaction with O-nucleophile to result in the tetrahydropyran skeleton as the key step.”

Uses for Akanocure Stereotetrad Lactones 4: lactone openings with sulfur nucleophiles

One of PolySciTech’s latest product offerings is Akanocure stereotetrad lactones (https://akinainc.com/polyscitech/products/akanocure/index.php) for use as synthetic precursors. There are many potential reactions for these lactones which can result in a wide array of useful molecules. In this series of postings, we will highlight potential uses of these materials. One potential reaction is the ring-opening of the lactone using sulfur (thiol) nucleophiles. Recently, this reaction has been applied to the synthesis of peloruside A, a potent chemotherapeutic agent. This research holds promise for improved availability of advanced chemotherapeutic agents. Read more: Raghavan, Sadagopan, and V. Vinoth Kumar. “A stereoselective synthesis of the C9–C19 subunit of (+)-peloruside A.” Organic & biomolecular chemistry 11, no. 17 (2013): 2847-2858. http://pubs.rsc.org/en/content/articlelanding/2013/ob/c3ob27508f#!divAbstract

“Abstract: The stereoselective synthesis of a C9–C19 fragment of the potent antitumor agent peloruside A is disclosed. The C11 stereogenic centre was created by a vinylogous Mukaiyama aldol reaction following Carreira’s protocol, with excellent stereocontrol. The C13 stereogenic centre was introduced by a substrate controlled reduction. The C15 stereocentre was fashioned using Noyori’s asymmetric transfer hydrogenation while the Z-trisubstituted double bond was formed by a regioselective hydrostannation of an alkyne followed by methylation of the resultant vinyl stannane using Lipshutz’s protocol. The C18 chiral centre was introduced by a chemoenzymatic route.”

Uses for Akanocure Stereotetrad Lactones 3: lactone openings with secondary nitrogen nucleophiles

One of PolySciTech’s latest product offerings is Akanocure stereotetrad lactones (https://akinainc.com/polyscitech/products/akanocure/index.php) for use as synthetic precursors. There are many potential reactions for these lactones which can result in a wide array of useful molecules. In this series of postings, we will highlight potential uses of these materials. These lactones can be ring-opened using secondary nitrogens as the nucleophilic agent. Previously, this reaction has been used to synthesize portions of Aplyronine A, a potent, chemotherapeutic marine macrolide. This research holds promise for enhanced synthesis of difficult-to-source chemotherapy agents. Read more: Hong, Wan Pyo, Mohammad N. Noshi, Ahmad El-Awa, and Philip L. Fuchs. “Synthesis of the C1–C20 and C15–C27 Segments of Aplyronine A.” Organic letters 13, no. 24 (2011): 6342-6345. http://pubs.acs.org/doi/abs/10.1021/ol2024746

“Abstract: The synthesis of C1–C20 and C15–C27 segments of Aplyronine A is described. Oxidative cleavage of cyclic vinyl sulfones has been used to prepare key fragments of Aplyronine A. Key precursors are united by Horner–Wadsworth–Emmons and Julia–Kociensky olefination for the respective elaboration of the C1–C20 and C15–C27 segments.”

Uses for Akanocure Stereotetrad Lactones 2b: lactone openings with primary nitrogen nucleophiles

One of PolySciTech’s latest product offerings is Akanocure stereotetrad lactones (https://akinainc.com/polyscitech/products/akanocure/index.php) for use as synthetic precursors. There are many potential reactions for these lactones which can result in a wide array of useful molecules. In this series of postings, we will highlight potential uses of these materials. One usage is opening the lactone ring utilizing primary nitrogens (amines). This method has been utilized to generate rhizopodin, a myxobacterial metabolite which is a potent actin-binding chemotherapeutic agent. This research holds promise for improved availability of effective chemotherapy agents. Read more: Dieckmann, Michael, Manuel Kretschmer, Pengfei Li, Sven Rudolph, Daniel Herkommer, and Dirk Menche. “Total synthesis of rhizopodin.” Angewandte Chemie International Edition 51, no. 23 (2012): 5667-5670. http://onlinelibrary.wiley.com/doi/10.1002/anie.201301978/full

“The total synthesis of the myxobacterial metabolite rhizopodin, a potent actin-binding anticancer agent, has been achieved. The modular synthesis utilizes a common C1–C22 monomeric unit to assemble the dimeric 38-membered macrodiolide core, which was elaborated by a bidirectional boron-mediated aldol reaction to install the characteristic side-chains. The final global deprotection was critically dependent on the correct choice of silyl protecting groups at C16/C16′.”

Uses for Akanocure Stereotetrad Lactones 2a: lactone openings with primary nitrogen nucleophiles

One of PolySciTech’s latest product offerings is Akanocure stereotetrad lactones (https://akinainc.com/polyscitech/products/akanocure/index.php) for use as synthetic precursors. There are many potential reactions for these lactones which can result in a wide array of useful molecules. In this series of postings, we will highlight potential uses of these materials. One usage is opening the lactone ring utilizing primary nitrogens (amines). For example, these can be utilized to generate aldonamides, a class of widely applicable precursors in and of themselves. You can read more about this application here: Metta-Magaña, Alejandro J., Reyna Reyes-Martínez, and Hugo Tlahuext. “Crystal structure and NMR spectroscopy of aldonamides derived from d-glycero-d-gulo-heptono-1, 4-lactone.” Carbohydrate research 342, no. 2 (2007): 243-253. http://www.sciencedirect.com/science/article/pii/S0008621506005325

“Abstract: We report the preparation of 12 aldonamides derived from d-glycero-d-gulo-heptono-1,4-lactone, their NMR characterization and study (13C, 1H, 15N NMR) in Me2SO-d6 solution. The evaluation of the coupling constants 3JH,H has shown that the sugar chain conformation in solution is all-trans for the studied amides. Because some amides crystallized, we discussed the crystal packing and found motifs. The conformation of the amides in the crystal structures displays two sickles at C2 and C3, with the exception of one that is all-trans. The bends cause the formation of the mean planes C1–C2–C3 and C3–C4–C5–C6–C7 with an average interplanar angle of 88°. We found three main kinds of crystal packing depending on the N-substituent; head-to-tail, bilayer and pseudo-hexagonal mode, all the three show hydrogen-bonding networks that stabilize the crystal lattice. Keywords: Aldonamides; Conformation; 15N NMR; Crystal packing; Hydrogen bonding”