ABSTRACT
Breast cancer has become the most commonly diagnosed cancer type in the world. A combination of chemotherapy and photothermal therapy (PTT) has emerged as a promising strategy for breast cancer therapy. However, the intricacy of precise delivery and the ability to initiate drug release in specific tumor sites remains a challenging puzzle. Therefore, to ensure that the therapeutic agents are synchronously delivered to the tumor site for their synergistic effect, a multifunctional nanoparticle system (PCRHNs) is developed, which is grafted onto the prussian blue nanoparticles (PB NPs) by reduction-responsive camptothecin (CPT) prodrug copolymer, and then modified with tumor-targeting peptide cyclo(Asp-d-Phe-Lys-Arg-Gly) (cRGD) and hyaluronic acid (HA). PCRHNs exhibited nano-sized structure with good monodispersity, high load efficiency of CPT, triggered CPT release in response to reduction environment, and excellent photothermal conversion under laser irradiation. Furthermore, PCRHNs can act as a photoacoustic imaging contrast agent-guided PTT. In vivo studies indicate that PCRHNs exhibited excellent biocompatibility, prolonged blood circulation, enhanced tumor accumulation, allow tumor-specific chemo-photothermal therapy to achieve synergistic antitumor effects with reduced systemic toxicity. Moreover, hyperthermia-induced upregulation of heat shock protein 70 in the tumor cells could be inhibited by CPT. Collectively, PCRHNs may be a promising therapeutic way for breast cancer therapy.
ABSTRACT
To develop a core-shell structure pDNA-CaPi-PLGA nanoparticles (CS-pDNA-CaPi-PLGA-NPs), calcium phosphate-pDNA nano complexes (CaPi-pDNA) were encapsulated inside of PLGA shells. The characteristics of the nanoparticles, including morphology, average particle size, zeta potential, entrapment efficiency, loading efficiency, stability in medium, pDNA protection ability from nuclease degradation, in vitro release, cytotoxicity and cell transfection were investigated and compared with the embedded structured CaPi modified PLGA nanoparticles (embedded-pDNA-CaPi-PLGA-NPs). The results showed that the obtained CS-pDNA-CaPi-PLGA-NPs were spherical in shape with an average particle size of (155 +/- 4.5) nm, zeta potentials of (-0.38 +/- 0.1) mV, entrapment efficiency of (80.56 +/- 2.5)% and loading efficiency of (1.16 +/- 0.04)%. The CS-pDNA-CaPi-PLGA-NPs were stable in the release media and could protect pDNA against nuclease degradation. And they also exhibited sustained release of pDNA in vitro. The highest gene transfection efficiency of the CS-pDNA-CaPi-PLGA-NPs in vitro reached (24.66 +/- 0.46)% (after 72 h transfection), which was significantly higher than that of free pDNA [(0.33 +/- 0.04)%, P < 0.01] and the pDNA-PLGA-NPs [(1.5 +/- 0.07)%, P < 0.01]. Besides, the transfection lasted for longer time than that of embedded-pDNA-CaPi-PLGA-NPs and the cytotoxicity of it was significantly lower than that of PEI (P < 0.01). These results indicate that CS-pDNA-CaPi-PLGA-NPs are a promising non-viral gene vector. Key words: gene delivery system; polylactic-co-glycolic acid; calcium phosphate; nanoparticle