Design and Evaluation of Peptide Amphiphiles with Different Hydrophobic Blocks for Simultaneous Delivery of Drugs and Genes

Abstract

In this study, peptides with six different compositions were designed and synthesized to study the effect of the structure of the hydrophobic block in triblock oligopeptide amphiphiles ((A(m) X)(n) H(5) K(15) ) on self-assembly properties, drug loading capacity and gene expression efficiency. The peptides were synthesized using a standard Fmoc-solid phase peptide synthesis protocol, which are A(12) H(5) K(15) , A(11) FH(5) K(15) , (A(5) F)(2) H(5) K(15) , (A(3) F)(3) H(5) K(15) , (AF)(6) H(5) K(15) and (AL)(6) H(5) K(15) . A(12) H(5) K(15) , A(11) FH(5) K(15) , (A(5) F)(2) H(5) K(15) and (A(3) F)(3) H(5) K(15) , formed micelles at concentrations above 200 mg · L(-1) with large size or aggregation. However, (AF)(6) H(5) K(15) and (AL)(6) H(5) K(15) had CMC values of 42 and 49 mg · L(-1) respectively, and the resulting micelles were much smaller in size as compared to the other peptide designs (108 and 233 nm for (AF)(6) H(5) K(15) and (AL)(6) H(5) K(15) , respectively). In addition, both peptides were able to load paclitaxel (PTX) into nanoparticles although PTX-loaded (AF)(6) H(5) K(15) nanoparticles had a smaller size (278 versus 295 nm, respectively). Encapsulation efficiency of PTX with (AF)(6) H(5) K(15) nanoparticles was 74%. Gene transfection studies showed that luciferase expression level induced by (AF)(6) H(5) K(15) micelles in HepG2 cell line was much higher than that mediated by (AL)(6) H(5) K(15) micelles at their respective optimal N/P ratios (3.2 × 10(8) versus 3.9 × 10(7) RLU · mg proteins(-1) ). Therefore, simultaneous delivery of PTX and luciferase-encoding plasmid was conducted using (AF)(6) H(5) K(15) micelles against HepG2 cells, and the results demonstrated that the co-delivery of PTX at 0.01 mg · L(-1) further increased luciferase expression level from 3.2 × 10(8) to 8.0 × 10(8) RLU · mg proteins(-1) at the optimal N/P ratio (i.e., 18). In summary, it is important to optimize the hydrophobic block of the oligopeptide amphiphiles in order to achieve desired properties for co-delivery of drugs and genes.

Synthesis and characterization of a biodegradable ABC triblock terpolymer as co‐delivery carrier of doxorubicin and DNA

“…Subsequently, the solution was added into a mixed cold solvent of hexane and diethyl ether (v/v 5 10 : 1). The precipitate was then collected and dried under vacuum at 25 C for 24 h to give the final product PEEP 50 -b-PCL 50 -b-PDMAEMA 25 (yield, 50%).…”

“…The chemical structures of polymers obtained in each step were confirmed by 1 H NMR analysis. Figure 1 shows the 1 H NMR spectra of representative polymers HOAPCL 50 ABr, PEEP 50 -b-PCL 50 , and PEEP 50 -b-PCL 50 -b-PDMAEMA 25 , respectively. All the characteristic peaks ascribed to the protons in the polymers can be found in the spectra.…”

“…The amino groups can be partially protonated at neutral or weakly acidic media, and changed into positively charged groups. Therefore, the nanoparticles formed from amphiphilic cationic copolymers have attracted widespread attentions for constructing co‐delivery carriers of genes and drugs . In our previous study, we reported a gene and drug carrier self‐assembled from triblock terpolymer mPEG‐ b ‐PCL‐ b ‐PDMAEMA, but the related in vitro biological tests were less investigated.…”

“…Therefore, the nanoparticles formed from amphiphilic cationic copolymers have attracted widespread attentions for constructing co-delivery carriers of genes and drugs. [22][23][24][25][26][27] In our previous study, we reported a gene and drug carrier self-assembled from triblock terpolymer mPEG-b-PCL-b-PDMAEMA, 28 but the related in vitro biological tests were less investigated. In addition, although hydrophilic poly(ethylene glycol) (PEG) has been approved by the United States Food and Drug Administration (FDA) and frequently used in biomedical applications, the non-biodegradability would somewhat limit their applications.…”

Folate Receptor–Targeted Polymeric Micellar Nanocarriers for Delivery of Orlistat as a Repurposed Drug against Triple-Negative Breast Cancer

“…Since polymers under a certain size limit are eventually cleared by the body, the use of polymer based NPs has the advantage of reducing systemic toxicity. Nanomedicine has witnessed significant recent advances, especially in development of drug delivery strategies for cancer treatment (8-12). Micelles, in particular, have been shown to increase drug water solubility, reduce non-specific toxicity, enhance permeability through membranes at the sub-100 nm level, and increase bioavailability (4).…”