Increased Cell Detachment Ratio of Mesenchymal-Type Lung Cancer Cells on pH-Responsive Chitosan through the ß3 Integrin.

Chitosan is sensitive to environmental pH values due to its electric property. This study investigates whether the pH-responsive chitosan assay can provide a simple method to evaluate the aggressive behavior of cancer cells with cell detachment ratio. The epithelial-mesenchymal transition (EMT) is induced with transforming growth factor-ß1 (TGF-ß1) in the human non-small cell lung cancer cell line (A549). EMT-induced cells and untreated cells are cultured on chitosan substrates at pH 6.99 for 24 h, followed by pH 7.65 for 1 h. The cell detachment ratio (CDR) on pH-responsive chitosan rises with an increasing of the TGF-ß1 concentration. The protein array reveals that the expression levels of the α2, α3, α5, ß2, and ß3 integrins are higher in EMT-induced A549 cells than in untreated cells. A further inhibition assay shows that adding ß3 integrin blocking antibodies significantly decreases the CDR of EMT-induced cells from 32.7 ± 5.7% to 17.8 ± 2.1%. The CDR of mesenchymal-type lung cancer cells increases on pH-responsive chitosan through the ß3 integrin. Notably, the CDR can be theoretically predicted according to the individual CDR on the pH-responsive chitosan surface, irrespective of heterogeneous cell mixture. The pH-responsive chitosan assay serves as a simple in vitro model to investigate the aggressive behavior of lung cancer including the heterogeneous cell population.

Intratumoral thermo-chemotherapeutic alginate hydrogel containing doxorubicin loaded PLGA nanoparticle and heating agent.

Chemotherapy has been widely used to treat cancer; however, the non-specific systemic toxicity of chemotherapeutic agents has always been an issue. Local injection treatment is a strategy used to reduce the undesired adverse effects of chemotherapeutic drugs. In addition, chemotherapeutic agents combined with thermotherapy are effective in further enhancing therapeutic potency. In the present study, we prepared an injectable hydrogel, namely, doxorubicin (DOX)-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticle (DPN) and magnetite nanoparticle (MNP) embedded in alginate hydrogel (DPN/MNP-HG), where DPN and MNP were the chemotherapeutic and heating agents, respectively, for intratumoral thermo-chemotherapy. Injectable DPN/MNP-HG, which possesses solid-like elastic properties, was conveniently prepared via ionic cross-linking at room-temperature. When exposed to an alternating magnetic field (AMF), DPN/MNP-HG exhibited controllable heat generation with a reversible temperature-rise profile. Regarding the kinetics of DOX release, both with and without AMF, DPN/MNP-HG exhibited a slow initial burst and sustained release profile. In cytotoxicity studies and subcutaneous mouse cancer models, successful thermo-chemotherapy with DPN/MNP-HG resulted in significantly lower cell viability and increased tumor-growth suppression; mice also exhibited good tolerance to injected DPN/MNP-HG both with(+) and without AMF application. In conclusion, the proposed thermo-chemotherapeutic DPN/MNP-HG for local intratumoral injection is a promising formulation for cancer treatment.

pH-driven continuous stem cell production with enhanced regenerative capacity from polyamide/chitosan surfaces.

Adipose-derived stem cells (ASCs) have raised significant interest for their potential therapeutic applications in regenerative medicine. However, ASCs usually suffer from decreased pluripotency and functional plasticity during in vitro expansion. Herein, this study sought to develop a continuous cell production system that can mass-produce ASCs with sustained regenerative capacity. The strategy was blending pH-responsive chitosan (CS) with polyamide-66 (PA) to generate combined surface properties with controllable cell growth/detachment ability to achieve a repeated cell production process. From the collected data, all the polymer blends were capable of completing a minimum of four consecutive production cycles, wherein the PA17CS blend (PA:CS = 1:7) outperformed with respect to the working effectiveness (average cell detachment ratio = 88%) and the cell viability. Compared to the trypsin-based method, ASCs harvested from PA17CS exhibited superior stemness characteristics along with SDF-1-mediated CXCR4 chemotactic response for stem cell homing. Moreover, injection of ASCs generated from PA17CS blend could more effectively induce neovascularization and protect skin flaps during an ischemic injury in a rat model.

Cell detachment ratio on pH-responsive chitosan: A useful biometric for prognostic judgment and drug efficacy assessment in oncology.

The inherently unpredictable complexity of tumors impedes the widespread practice of the molecular biomarkers in outcome prediction. Alternatively, from the biophysical perspective, this study sought to investigate the applicability of the cell detachment ratio (CDR) derived from pH-responsive chitosan as a biometrical identifier for the disease state in cancer prognostic judgment and drug efficacy assessment. In the targeted therapy model, the repression of tumor dissemination in cells harboring aberrant ErbB signals (human non-small cell lung cancer cell line PC9 and breast cancer cell line BT474) were first demonstrated both in vitro and in vivo. Consequently, the corresponding CDR profile goes synchronously with the extent of cancer regression in response to the medication. Definitive integrins that drive the cell detachment were also verified through CDR examination following the integrin functional blockade. Conclusively, CDR is a promising clinical index for evaluation of the metastatic cell behaviors in terms of the cell detachment.

Doxorubicin Loaded PLGA Nanoparticle with Cationic/Anionic Polyelectrolyte Decoration: Characterization, and Its Therapeutic Potency.

Optimized Doxorubicin hydrochloride (DOX) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (DPN) were prepared by controlling the water/oil distribution of DOX at different pH solutions and controlling the electrostatic interaction between DOX and different terminated-end PLGAs. Furthermore, cationic polyethylenimine (PEI) and anionic poly (acrylic acid) (PAA) were alternately deposited on DPN surface to form PEI-DPN (IDPN) and PAA-PEI-DPN (AIDPN) to enhance cancer therapy potency. Compared to DPN, IDPN exhibited a slower release rate in physiological conditions but PEI was demonstrated to increase the efficiency of cellular uptake and endo/lysosomal escape ability. AIDPN, with the outermost negatively charged PAA layer, still retained better endo/lysosomal escape ability compared to DPN. In addition, AIDPN exhibited the best pH-dependent release profile with 1.6 times higher drug release in pH 5.5 than in pH 7.4. Therefore, AIDPN with the characteristics of PEI and PAA simultaneously was the most optional cancer therapy choice within these three PLGA nanoparticles. As the proposed nanoparticles integrated optimal procedure factors, and possessed cationic and anionic outlayer, our drug delivery nanoparticles can provide an alternative solution to current drug delivery technologies.

Label-free platform on pH-responsive chitosan: Adhesive heterogeneity for cancer stem-like cell isolation from A549 cells via integrin ß4.

Great efforts have been paid to develop methodologies for cancer stem-like cell (CSLC) isolation in anti-cancer research. The major obstacle lies in the lack of generic biomarkers for different cancer types and the requirement of complicated immuno-labeling procedures. The purpose of this study is to establish a label-free platform for CSLC isolation using pH-responsive chitosan. Based on the adhesive heterogeneity, 15.7 ± 1.9 % of human non-small cell lung cancer (NSCLC) cell line A549 detached from the chitosan substrate following medium pH elevation from 6.99 to 7.65 within 1 h. As a result, this subpopulation of cells with low adhesiveness exhibited superior CSLC hallmarks, including self-renewal, invasive and metastatic potential, therapeutic-resistance, colony formation in vitro, as well as nude mice xenograft in vivo for tumorigenesis, in comparison with their high-adhesive counterpart. Furthermore, integrin ß4 is decisive in controlling CSLC detachment of NSCLC. Conclusively, this pH-dependent isolation provides new insights into biomaterial-based CSLC isolation.

NF-kappaB inhibitors significantly attenuate the transcription of high affinity type-2 cationic amino acid transporter in LPS-stimulated rat kidney.

BACKGROUND: Sepsis-induced renal failure is closely related to inducible nitric oxide synthase (iNOS) upregulation and nitric oxide (NO) overproduction. Trans-membrane L-arginine transportation mediated by type-2 cationic amino acid transporter (CAT-2) isozymes, including CAT-2, CAT-2A, and CAT-2B, is one of the crucial mechanisms that regulate NO biosynthesis by iNOS. We previously had shown that endotoxemia significantly upregulated renal CAT-2 and CAT-2B but not CAT-2A expression. This study was, thus, conducted to further explore the role of nuclear factor-kappaB (NF-kappaB) in regulating the expression of CAT-2 isozymes in lipopolysaccharide (LPS)-treated rat kidney. METHODS: Adult male Sprague-Dawley rats were randomly given intra-peritoneal injections of normal saline (N/S), LPS, LPS plus NF-kappaB inhibitor pre-treatment (PDTC, dexamethasone, or salicylate), or an NF-kappaB inhibitor alone. The rats were sacrificed at 6 hours after LPS injection and enzyme expression and renal injury were examined. RESULTS: Renal iNOS, CAT-2, and CAT-2B were significantly upregulated in LPS-stimulated rat kidney. NF-kappa B inhibitors significantly attenuated this upregulation induced by LPS and resultantly attenuated renal NO biosynthesis and renal injury induced by LPS. In contrast, renal CAT-2A expression was not affected by either LPS or NF-kappaB inhibitors. CONCLUSIONS: LPS co-induces iNOS, CAT-2 and CAT-2B expression in LPS-stimulated rat kidney. Furthermore, inhibition of NF-kappaB significantly attenuates NO biosynthesis through inhibition of iNOS, CAT-2, and CAT-2B, and, in turn, significantly reduces endotoxemia-induced renal injury.