Synthesis and Properties of Star-Shaped Polylactide Attached to Poly(Amidoamine) Dendrimer

Cai, Qing; Zhao, Youliang; Bei, Jianzhong; Xi, Fu; Wang, Shenguo

doi:10.1021/bm034051a

“…The molecular structure and properties of 6-s-PLGA were confirmed through 13 C NMR, FTIR, gel permeation chromatography, and DSC. The polymer has good biocompatibility and the 6-s-PTX-PLGA-NPs exhibited a smaller size distribution and higher drug-loading capacity than the L-PTX-PLGA-NPs.…”

Section: Resultsmentioning

confidence: 99%

“…These largely determine the properties of the polymer and transport the encapsulated drugs to the targeted organs and tissues. [11][12][13] Currently, most star-shaped polymers in use are of three or four arms (Figure 1). However, the more arms the star-shaped polymer has, the more sites can be modified and the higher encapsulation efficiency it will have.…”

mentioning

confidence: 99%

Synthesis, characterization, and evaluation of paclitaxel loaded in six-arm star-shaped poly(lactic-co-glycolic acid)

Chen¹,

Yang²,

Liu³

et al. 2013

IJN

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Background Star-shaped polymers provide more terminal groups, and are promising for application in drug-delivery systems. Methods A new series of six-arm star-shaped poly(lactic-co-glycolic acid) (6-s-PLGA) was synthesized by ring-opening polymerization. The structure and properties of the 6-s-PLGA were characterized by carbon-13 nuclear magnetic resonance spectroscopy, infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry. Then, paclitaxel-loaded six-arm star-shaped poly(lactic-co-glycolic acid) nanoparticles (6-s-PLGA-PTX-NPs) were prepared under the conditions optimized by the orthogonal testing. High-performance liquid chromatography was used to analyze the nanoparticles’ encapsulation efficiency and drug-loading capacity, dynamic light scattering was used to determine their size and size distribution, and transmission electron microscopy was used to evaluate their morphology. The release performance of the 6-s-PLGA-PTX-NPs in vitro and the cytostatic effect of 6-s-PLGA-PTX-NPs were investigated in comparison with paclitaxel-loaded linear poly(lactic-co-glycolic acid) nanoparticles (L-PLGA-PTX-NPs). Results The results of carbon-13 nuclear magnetic resonance spectroscopy and infrared spectroscopy suggest that the polymerization was successfully initiated by inositol and confirm the structure of 6-s-PLGA. The molecular weights of a series of 6-s-PLGAs had a ratio corresponding to the molar ratio of raw materials to initiator. Differential scanning calorimetry revealed that the 6-s-PLGA had a low glass transition temperature of 40°C–50°C. The 6-s-PLGA-PTX-NPs were monodispersed with an average diameter of 240.4±6.9 nm in water, which was further confirmed by transmission electron microscopy. The encapsulation efficiency of the 6-s-PLGA-PTX-NPs was higher than that of the L-PLGA-PTX-NPs. In terms of the in vitro release of nanoparticles, paclitaxel (PTX) was released more slowly and more steadily from 6-s-PLGA than from linear poly(lactic-co-glycolic acid). In the cytostatic study, the 6-s-PLGA-PTX-NPs and L-PLGA-PTX-NPs were found to have a similar antiproliferative effect, which indicates durable efficacy due to the slower release of the PTX when loaded in 6-s-PLGA. Conclusion The results suggest that 6-s-PLGA may be promising for application in PTX delivery to enhance sustained antiproliferative therapy.

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“…Briefly returning to the benefits of dendritic clusters over conventional polymers for drug delivery, problems with the delivery of covalent conjugates when conven-tional polymers, such as poly(lactic acid) (PLA) or its copolymer with glycolide (PLGA), are used include a lack of sustained drug release [91]. Generally, these and other linear, randomly oriented polymers have an initial burst where as much as 50% of drug is released followed by a dramatic drop-off.…”

Section: Release Of Covalently-delivered ''Pro-drugs''mentioning

confidence: 99%

Dendrimers in Cancer Treatment and Diagnosis

Sampathkumar

¹

,

Yarema

²

2003

Nanotechnologies for the Life Sciences

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The sections in this article are Overview Introduction Basic Properties and Applications of Dendrimers Structural Features and Chemical and Biological Properties Basic Features of Dendritic Macromolecules are Inspired by Nature Comparison of the Properties of Dendrimers and Conventional Synthetic Polymers Comparison of the Properties of Dendrimers and Proteins (a Biological Polymer) Dendritic Macromolecules Possess a Wealth of Possible Applications Methods for Dendrimer Synthesis History and Basic Strategies Cascade Reactions are the Foundation of Dendrimer Synthesis Dendrimer Synthesis has Expanded Dramatically in the Past Two Decades Strategies, Cores, and Building Blocks for Dendritic Macromolecules Dendrimers are Constructed from Simple “Building Blocks” The Synthesis of Dendrimers Follows Either a Divergent or Convergent Approach Heterogeneously‐functionalized Dendrimers Basic Description and Synthetic Considerations Glycosylation is an Example of Surface Modification with Multiple Bioactivities Dendrimers in Drug Delivery Dendrimers are Versatile Nano‐devices for the Delivery of Diverse Classes of Drugs Dendritic Drug Delivery: Encapsulation of Guest Molecules Dendrimers have Internal Cavities that can Host Encapsulated Guest Molecules Using Dendrimers for Gene Delivery Release of Encapsulated “Pro‐drugs” Covalent Conjugation Strategies Dendrimers Overcome many Limitations Inherent in Polymeric Conjugation Strategies Dendrimer Conjugates can be Used as Vaccines Release of Covalently‐delivered “Pro‐drugs” Fine‐tuning Dendrimer Properties to Facilitate Delivery and Ensure Bioactivity Delivery Requires Avoiding Non‐specific Uptake “Local” Considerations: Contact with, and Uptake by, the Target Cell Drug Delivery: Ensuring the Biocompatibility of Dendritic Delivery Vehicles Biocompatibility Entails Avoiding “Side Effects” such as Toxicity and Immunogenicity Water Solubility and Immunogenicity Inherent and Induced Toxicity Dendrimers in Cancer Diagnosis and Treatment Dendrimers have Attractive Properties for Cancer Treatment Dendrimer‐sized Particles Passively Accumulate at the Sites of Tumors Multifunctional Dendrimers can Selectively Target Biomarkers found on Cancer Cells Methods for Targeting Specific Biomarkers of Cancer Targeting by Folate, a Small Molecule Ligand Targeting by Monoclonal Antibodies Dendrimers in Cancer Diagnosis and Imaging Labeled Dendrimers are Important Research Tools for Biodistribution Studies Towards Clinical Use: MRI Imaging Agents Steps Towards the Clinical Realization of Dendrimer‐based Cancer Therapies The Stage is now set for Dendrimer‐based Cancer Therapy Boron Neutron Capture Therapy Innovations Promise to Speed Progress “Mix‐and‐Match” Strategy of Bifunctional Dendritic Clusters Towards Therapeutic Exploitation of Glycosylation Abnormalities found in Cancer Towards Targeting Metabolically‐engineered Carbohydrate Epitopes Concluding Remarks Acknowledgments

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“…For example, their strong hydrophobicity often results in protein adsorption and subsequent nonspecific uptake by the reticuloendothelial system after intravenous injection. In order to overcome the defect of polyesters, hydrophilic blocks have been incorporated into their backbones (e.g., Cai, Q; Chen, H.T; Okuda, T, Gillies, E.R; Guillaudeu, S.J et al [4,5,6,7,8,9,10]). In drug delivery system, hydrophilic poly(ethylene glycol) (PEG) block is more frequently introduced into biodegradable polyesters.…”

Section: Introductionmentioning

confidence: 99%

The preparation of phosphorylcholine-containing poly(Llactide) nanoparticles with solvent evaporation method

Cao¹,

Chen²,

Chen³

et al. 2010

E-Polymers

1

0

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Phosphorylcholine-containing poly(L-lactide) (PLLA-PC) is a kind of amphiphilic copolymer synthesized with L-lactide (LLA) as monomer and glycerophosphorylcholine as ring-opening reagent. In this paper, self-assembly nanoparticles of PLLA-PC were prepared with solvent evaporation method. The factors that affected the properties and stability of nanoparticles were investigated. Transmission electron microscope (TEM) indicated that PLLA-PC nanoparticles presented typical core/shell structure. The critical micelle concentration (CMC) was determined with fluorescent probe method. The results showed that the CMCs were quite low (< 1×10 -3 g/l) and were dependent on LLA units in the copolymer. The size of the nanoparticles was detected by dynamic light scattering (DLS). The results indicated that the size could be affected by LLA units, the amount of solvent and water in the preparation process. On the other hand, the obtained nanoparticles were stable while being stored at 4 0 C, and hardly changed over the dilution with water, which was of great importance in venous injection. The solubility of clofazimine was better in aqueous solution of PLLA-PC nanoparticles than in pure water. This preliminary study suggested that PLLA-PC nanoparticles had a great potential as delivery system for hydrophobic drug.

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Synthesis and Properties of Star-Shaped Polylactide Attached to Poly(Amidoamine) Dendrimer

Cited by 150 publications

References 36 publications

Synthesis, characterization, and evaluation of paclitaxel loaded in six-arm star-shaped poly(lactic-co-glycolic acid)

Synthesis, characterization, and evaluation of paclitaxel loaded in six-arm star-shaped poly(lactic-co-glycolic acid)

Dendrimers in Cancer Treatment and Diagnosis

The preparation of phosphorylcholine-containing poly(Llactide) nanoparticles with solvent evaporation method

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