Encapsulation and Residency of a Hydrophobic Dye within the Water-Filled Interior of a PAMAM Dendrimer Molecule

2017 ◽  
Vol 121 (8) ◽  
pp. 1930-1940 ◽  
Author(s):  
Somnath Koley ◽  
Subhadip Ghosh
Nanoscale ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 2703-2713
Author(s):  
James Magnus Rae ◽  
Barbara Jachimska

For the first time in literature, we show that a G5.5 PAMAM dendrimer molecule can have an effective negative or positive charge depending on environmental conditions. Control of the molecules charge enables its specific interaction with proteins.


2020 ◽  
Vol 20 (15) ◽  
pp. 1857-1872
Author(s):  
Alberto M. Muñoz ◽  
Manuel J. Fragoso-Vázquez ◽  
Berenice P. Martel ◽  
Alma Chávez-Blanco ◽  
Alfonso Dueñas-González ◽  
...  

Background: Our research group has developed some Valproic Acid (VPA) derivatives employed as anti-proliferative compounds targeting the HDAC8 enzyme. However, some of these compounds are poorly soluble in water. Objective: Employed the four generations of Polyamidoamine (G4 PAMAM) dendrimers as drug carriers of these compounds to increase their water solubility for further in vitro evaluation. Methods: VPA derivatives were subjected to Docking and Molecular Dynamics (MD) simulations to evaluate their affinity on G4 PAMAM. Then, HPLC-UV/VIS, 1H NMR, MALDI-TOF and atomic force microscopy were employed to establish the formation of the drug-G4 PAMAM complexes. Results: The docking results showed that the amide groups of VPA derivatives make polar interactions with G4 PAMAM, whereas MD simulations corroborated the stability of the complexes. HPLC UV/VIS experiments showed an increase in the drug water solubility which was found to be directly proportional to the amount of G4 PAMAM. 1H NMR showed a disappearance of the proton amine group signals, correlating with docking results. MALDI-TOF and atomic force microscopy suggested the drug-G4 PAMAM dendrimer complexes formation. Discussion: In vitro studies showed that G4 PAMAM has toxicity in the micromolar concentration in MDAMB- 231, MCF7, and 3T3-L1 cell lines. VPA CF-G4 PAMAM dendrimer complex showed anti-proliferative properties in the micromolar concentration in MCF-7 and 3T3-L1, and in the milimolar concentration in MDAMB- 231, whereas VPA MF-G4 PAMAM dendrimer complex didn’t show effects on the three cell lines employed. Conclusion: These results demonstrate that G4 PAMAM dendrimers are capableof transporting poorly watersoluble aryl-VPA derivate compounds to increase its cytotoxic activity against neoplastic cell lines.


2021 ◽  
Vol 22 (4) ◽  
pp. 1982 ◽  
Author(s):  
Aleksandra Kaczorowska ◽  
Małgorzata Malinga-Drozd ◽  
Wojciech Kałas ◽  
Marta Kopaczyńska ◽  
Stanisław Wołowiec ◽  
...  

Polyamidoamine PAMAM dendrimer generation 3 (G3) was modified by attachment of biotin via amide bond and glucoheptoamidated by addition of α-D-glucoheptono-1,4-lacton to obtain a series of conjugates with a variable number of biotin residues. The composition of conjugates was determined by detailed 1-D and 2-D NMR spectroscopy to reveal the number of biotin residues, which were 1, 2, 4, 6, or 8, while the number of glucoheptoamide residues substituted most of the remaining primary amine groups of PAMAM G3. The conjugates were then used as host molecules to encapsulate the 5-aminolevulinic acid. The solubility of 5-aminolevulinic acid increased twice in the presence of the 5-mM guest in water. The interaction between host and guest was accompanied by deprotonation of the carboxylic group of 5-aminolevulinic acid and proton transfer into internal ternary nitrogen atoms of the guest as evidenced by a characteristic chemical shift of resonances in the 1H NMR spectrum of associates. The guest molecules were most likely encapsulated inside inner shell voids of the host. The number of guest molecules depended on the number of biotin residues of the host, which was 15 for non-biotin-containing glucoheptoamidated G3 down to 6 for glucoheptoamidated G3 with 8 biotin residues on the host surface. The encapsulates were not cytotoxic against Caco-2 cells up to 200-µM concentration in the dark. All encapsulates were able to deliver 5-aminolevulinic acid to cells but aqueous encapsulates were more active in this regard. Simultaneously, the reactive oxygen species were detected by staining with H2DCFDA in Caco-2 cells incubated with encapsulates. The amount of PpIX was sufficient for induction of reactive oxygen species upon 30-s illumination with a 655-nm laser beam.


Author(s):  
Dilgeş Baskın ◽  
Özge Yılmaz ◽  
Muhammad Nazrul Islam ◽  
Metin Tülü ◽  
İkbal Koyuncu ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 995
Author(s):  
Yucheng Peng ◽  
Xiaomeng Wang ◽  
Yue Wang ◽  
Yue Gao ◽  
Rui Guo ◽  
...  

The design of multimodal imaging nanoplatforms with improved tumor accumulation represents a major trend in the current development of precision nanomedicine. To this end, we report herein the preparation of macrophage (MA)-laden gold nanoflowers (NFs) embedded with ultrasmall iron oxide nanoparticles (USIO NPs) for enhanced dual-mode computed tomography (CT) and magnetic resonance (MR) imaging of tumors. In this work, generation 5 poly(amidoamine) (G5 PAMAM) dendrimer-stabilized gold (Au) NPs were conjugated with sodium citrate-stabilized USIO NPs to form hybrid seed particles for the subsequent growth of Au nanoflowers (NFs). Afterwards, the remaining terminal amines of dendrimers were acetylated to form the dendrimer-stabilized Fe3O4/Au NFs (for short, Fe3O4/Au DSNFs). The acquired Fe3O4/Au DSNFs possess an average size around 90 nm, display a high r1 relaxivity (1.22 mM−1 s−1), and exhibit good colloidal stability and cytocompatibility. The created hybrid DSNFs can be loaded within MAs without producing any toxicity to the cells. Through the mediation of MAs with a tumor homing and immune evasion property, the Fe3O4/Au DSNFs can be delivered to tumors more efficiently than those without MAs after intravenous injection, thus significantly improving the MR/CT imaging performance of tumors. The developed MA-mediated delivery system may hold great promise for enhanced tumor delivery of other contrast agents or nanomedicines for precision cancer nanomedicine applications.


2021 ◽  
Author(s):  
Fangfang Ma ◽  
Gaoshun Ge ◽  
Yizhen Fang ◽  
Erru Ni ◽  
Yuanyuan Su ◽  
...  

Rapid and accurate identification of cardiac troponin I (cTnl) in biological fluids is very essential for judging acute myocardial infarction (AMI). Herein, we constructed an enzyme-free electrochemical immunosensing system for...


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