Novel peptide–dendrimer conjugates as drug carriers for targeting nonsmall cell lung cancer

Figures & data

Table 1 The displayed peptide sequences of screening phage from in vivo lung cancer xenografts

Phage clone	Peptide sequence	Frequency
A-2	ACPLSHSLIC	28/37
A-7	ACSVAPDNLC	3/37
B-11	ACAQSYHVWC	2/37
A-6	ACWFSNIAKC	1/37
A-13	ACSHFVYGIC	1/37
B-3	ACVNGRMTDC	1/37
B-7	ACPLKANLSC	1/37

Notes: Forty phage clones were random selected from two plates (A and B) and 37 phage displayed peptide sequences were identified. The first, second, and tenth residues are alanine, cysteine, and cysteine, respectively. The inner random seven peptides were cyclized by the two cysteine residues.

Figure 1 Synthetic scheme of polyamidoamine dendrimer generation 4 fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide.

Figure 2 Ultraviolet-visible spectra of the synthesized polyamidoamine conjugates. The peak at 500 nm indicates the presence of fluorescence-labeling in the conjugates. The peptide adsorbance peak at 275 nm was overlapped with the broad adsorbance peak of fluorescence-labeling at 275 nm.

Figure 3 MTT assay for cellular toxicity of 293T cells. Cells were incubated with polyamidoamine, fluorescence-labeled acetylated polyamidoamine, acetylated polyamidoamine and fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide, at varied concentrations. The viability of the nontreated cells was arbitrarily defined as 100%. Data are expressed as mean ± standard deviation (n = 6).

Figure 4 In vitro evaluation of dose-dependent uptake of the conjugates (fluorescence-labeled acetylated polyamidoamine and fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide) by 293T cells (A) and NCI-H460 cells (B) determined by fluorescence-activated cell sorting. The cells were incubated with various concentrations of the conjugates for 4 hours at 37°C. C) Time-dependent uptake of the conjugates by NCI-H460 cells. The NCI-H460 cells were incubated with the conjugates at a concentration of 0.25 μM for different time. D) Uptake of the conjugates by 293T and NCI-H460 cells. The incubation conditions were 0.5 μM and four hours.

Figure 5 In vitro evaluation of the conjugates (fluorescence-labeled acetylated polyamidoamine and fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide) targeting to 293T and NCI-H460 cells determined by inverted fluorescence microscopy. The cells were incubated with the conjugates (0.5 μM) for 4 hours. 100 × (A) 293T cells incubated with fluorescence-labeled acetylated polyamidoamine. B) 293T cells incubated with fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide. C) NCI-H460 cells incubated with fluorescence-labeled acetylated polyamidoamine. D) NCI-H460 cells incubated with fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide. E) local amplification of D.

Figure 6 Distribution of fluorescence-labeled acetylated polyamidoamine and fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide 4 hours postinjection in athymic mice bearing nonsmall cell lung cancer tumor xenografts, the relative fluorescence intensity per unit area data are presented as mean ± standard deviation (n = 6, **P < 0.01 fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide versus fluorescence-labeled acetylated polyamidoamine in tumor).

Figure S1 ¹H nuclear magnetic resonance spectrum (300 mHz,D₂O) of the acetylated polyamidoamine.

Figure S2 ¹H nuclear magnetic resonance spectrum (300 mHz,D₂O) of the fluorescence-labeled acetylated polyamidoamine.

Figure S3 ¹H nuclear magnetic resonance spectrum (300 mHz, D₂O) of the fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide.

Figure S4 Laser light-scattering assay results. The polyamidoamine particle size was about 7 nm (A) and the particle size of acetylated polyamidoamine (B) fluorescence-labeled acetylated polyamidoamine (C), and fluorescence-labeled acetylated polyamidoamine lung cancer targeting peptide (D) becomes bigger and bigger.