Investigation of antitumor activities of trastuzumab delivered by PLGA nanoparticles

Abstract

Background We report the development of an efficient antibody delivery system for the incorporation of trastuzumab (TZ) into poly(lactic- co -glycolic) acid nanoparticles (PLGA NPs). The aim of the work was to overcome the current limitations in the clinical use of therapeutic antibodies, including immunogenicity, poor pharmacokinetics, low tumor penetration and safety issues. Materials and methods Trastuzumab-loaded PLGA NPs (PLGA-TZ) were synthesized according to a double emulsion method. The same protocol was used to produce control batches of nonspecific IgG-loaded NPs and empty PLGA NPs. After release of TZ from PLGA NPs, the effects on the main biological activities of the antibody were evaluated on SKBR3 (human epidermal growth factor receptor 2 [HER2]-positive breast cancer cell line), including specific binding to HER2, phosphorylation of HER2 (Y1248), degradation of HER2 protein and antibody-dependent cell-mediated cytotoxicity (ADCC) mechanism. In addition, an MTT assay was performed for treating SKBR3 cells with PLGA NPs loaded with TZ and doxorubicin to evaluate the cytotoxic activity of the combined treatment. Results and discussion TZ was gradually released in a prolonged way over 30 days. The physical characterization performed with circular dichroism, Fourier transform infrared and fluorescence spectroscopy of TZ after release demonstrated that no structural alterations occurred compared to the native antibody. In vitro experiments using SKBR3 cells showed that TZ released from PLGA NPs maintained the same biological activity of native TZ. PLGA NPs allowed a good co-encapsulation efficiency of TZ and doxorubicin resulting in improved therapy. Conclusion With the TZ case study, we demonstrate that the distinctive features of therapeutic monoclonal antibodies, including molecular targeting efficiency, capability to inhibit or properly affect the regulatory signaling pathways of cancer cells and stimulation of the ADCC, are fully preserved after loading into and release from PLGA NPs. In addition, PLGA NPs are shown to allow for the simultaneous incorporation of TZ and conventional chemotherapeutics, resulting in a potent antitumor nanodrug well suited for in situ combination and neoadjuvant therapy.

PLGA protein nanocarriers with tailor-made fluorescence/MRI/PET imaging modalities

“…6,7 Moreover, PLGA-based nanocarriers have been used as drug delivery systems to administer proteins, 8,9 DNA 10 and anticancer drugs among others. 1,11,12 Nonetheless, despite their compositional similarities, any novel PLGA-based drug delivery system will require a thorough evaluation to address potential toxicity issues and study the pharmacokinetics and the pharmacodynamics of each specific carrier. Such preclinical in vitro and in vivo studies, comprising multiple biological characterization phases, could be expedited by endowing the carrier with complementary imaging capacities.…”

<p>Cetuximab-Coated Thermo-Sensitive Liposomes Loaded with Magnetic Nanoparticles and Doxorubicin for Targeted EGFR-Expressing Breast Cancer Combined Therapy</p>

“… 28 Recently, various researchers have demonstrated the selective internalization of monoclonal antibody-modified nanoparticles in comparison to non-modified nanoparticles. 29 , 30 …”

PLGA nanoparticle preparations by emulsification and nanoprecipitation techniques: effects of formulation parameters

“…PLGA is successfully used in the research of drug delivery systems, because of its biodegradability and low systemic toxicity, it has also been approved by the US Food and Drug Administration (FDA) for medical applications. [8][9][10][11] PLGA can be formulated as PNP using several different methods, such as emulsicationevaporation, nanoprecipitation or solvent displacement, solvent diffusion, and phase-inversion; with sizes ranging from 10 to 1000 nm. 12,13 When encapsulating hydrophobic compounds, two of the most commonly used techniques are the emulsication-solvent evaporation technique and the nanoprecipitation technique.…”