In the following study, we describe the preparation and characterization of poly(ethylene glycol) (PEG) and biotin modified, doxorubicin (DOX) loaded silica nanoparticles (Dox/SLN-PEG-Biotin), which was employed as a drug delivery system for colon cancer therapy. The DOX/SLN-PEG-Biotin exhibited small particle size and low cytotoxicity in vitro. Moreover, the Dox releases from DOX/SLN-PEG-Biotin followed a redox-sensitive behavior. Biotin functionalized Dox/SLN-PEG-Biotin demonstrated tumor-targeted delivery of their payload, resulting in enhanced cellular uptake in HCT116 tumor cells and potentiated tumor accumulation in HCT116 tumor-bearing mice. In particular, in vivo anti-cancer assay confirmed that DOX/SLN-PEG-Biotin as a tumor-targeted delivery system exerted strong anti-cancer efficacy. Altogether, DOX chemotherapy using DOX/SLN-PEG-Biotin might be an effective strategy for improved treatment in colon cancer.

Peri-implant infection control is crucial for implant fixation and durability. Antimicrobial administration approaches to control peri-implant infection are far from satisfactory. During bacterial infection, pH level around the peri-implant surface decreases as low as pH 5.5. This change of pH can be used as a switch to control antimicrobial drug release from the implant surface. Silver nanoparticles (AgNPs) have broad-spectrum antimicrobial properties. In this study, we aimed to design a pH-dependent AgNPs releasing titania nanotube arrays (TNT) implant for peri-implant infection control. The nanotube arrays were fabricated on the surface of titanium implant as containers; AgNPs were grafted on TNT implant surface via a low pH-sensitive acetal linker (TNT-AL-AgNPs). SEM, TEM, AFM, FTIR as well as XPS data showed that AgNPs have been successfully linked to TNT via acetal linker without affecting the physicochemical characteristics of TNT. The pH 5.5 enhanced AgNPs release from TNT-AL-AgNPs implant compared with pH 7.4. AgNPs released at pH 5.5 robustly increased antimicrobial activities against gram-positive and gram-negative bacteria compared with AgNPs released at pH 7.4. TNT-AL-AgNPs implant enhanced osteoblast proliferation, differentiation, and did not affect osteoblast morphology in vitro. In conclusion, incorporation of AgNPs in TNT via acetal linker maintained the surface characteristics of TNT. TNT-AL-AgNPs implant was biocompatible to osteoblasts and showed osteoinductive properties. AgNPs were released from TNT-AL-AgNPs implant in high dose at pH 5.5, and this release showed strong antimicrobial properties in vitro. Therefore, this novel design of low pH-triggered AgNPs releasing TNT-AL-AgNPs could be an infection-triggered antimicrobial releasing implant model to control peri-implant infection.

Curcumin can inhibit the growth of a variety of cancer cells; however, its poor bioavailability and pharmacokinetic profiles, which are attributed to its instability under physiological conditions, have limited its application in anticancer therapy. In the present study, we screened a double carbonyl analog of curcumin (A17) and analyzed its effects and mechanism of inducing apoptosis in human lung cancer H460 cells. The results showed that A17 not only induced CHOP expression in human lung cancer H460 cells, but also induced the apoptosis of H460 cells in a dose-responsive manner, and this effect was related to corresponding activation of some important components in the endoplasmic reticulum (ER) stress-mediated apoptosis pathway. When CHOP was knocked down by specific siRNA, A17-induced cell apoptosis was attenuated, thereby further demonstrating that the apoptotic pathway is ER stress‑dependent. Our studies demonstrated that A17 has better stability and antitumor activity than curcumin in H460 cells via an ER stress-mediated mechanism. These results imply that A17 could be further explored as a potential anticancer agent for the treatment of human non-small cell lung cancer (NSCLC).

BACKGROUND:The transcription factor nuclear factor-κB (NF-κB) is constitutively activated in a variety of human cancers, including gastric cancer. NF-κB inhibitors that selectively kill cancer cells are urgently needed for cancer treatment. Curcumin is a potent inhibitor of NF-κB activation. Unfortunately, the therapeutic potential of curcumin is limited by its relatively low potency and poor cellular bioavailability. In this study, we presented a novel NF-κB inhibitor named Da0324, a synthetic asymmetric mono-carbonyl analog of curcumin. The purpose of this study is to research the expression of NF-κB in gastric cancer and the antitumor activity and mechanism of Da0324 on human gastric cancer cells.METHODS:The expressions between gastric cancer tissues/cells and normal gastric tissues/cells of NF-κB were evaluated by Western blot. The inhibition viability of compounds on human gastric cancer cell lines SGC-7901, BGC-823, MGC-803, and normal gastric mucosa epithelial cell line GES-1 was assessed with the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Absorption spectrum method and high-performance liquid chromatography method detected the stability of the compound in vitro. The compound-induced changes of inducible NF-κB activation in the SGC-7901 and BGC-823 cells were examined by Western blot analysis and immunofluorescence methods. The antitumor activity of compound was performed by clonogenic assay, matrigel invasion assay, flow cytometric analysis, Western blot analysis, and Hoechst 33258 staining assay.RESULTS:High levels of p65 were found in gastric cancer tissues and cells. Da0324 displayed higher growth inhibition against several types of gastric cancer cell lines and showed relatively low toxicity to GES-1. Moreover, Da0324 was more stable than curcumin in vitro. Western blot analysis and immunofluorescence methods showed that Da0324 blocked NF-κB activation. In addition, Da0324 significantly inhibited tumor proliferation and invasion, arrested the cell cycle, and induced apoptosis in vitro.CONCLUSION:The asymmetric mono-carbonyl analog of curcumin Da0324 exhibited significantly improved antigastric cancer activity. Da0324 may be a promising NF-κB inhibitor for the selective targeting of cancer cells. However, further studies are needed in animals to validate these findings for the therapeutic use of Da0324.

Fibroblast growth factor 2 (FGF2) is closely involved in a variety of tumors, including gastric cancer (GC). FGF2 inhibitors exert good antitumor activity, but no FGF2 inhibitor has been employed for clinical use. To obtain a low-toxicity, stable peptidomimetic (called P29) target to FGF2, the affinity between P29 and FGF2 was detected by surface plasmon resonance. The stability of P29 was measured by high performance liquid chromatography. MTT assay and transwell assay were used to access the proliferative and invasive ability of GC cells, respectively. Western blot assay and flow cytometric analysis were applied to study the mechanism of P29. P29 possessed high affinity with FGF2 and a longer half-life in vitro. P29 suppressed the FGF2-induced proliferation of GC cells. It also inhibited the phosphorylation of FRS2, ERK1/2, and AKT triggered by FGF2 in GC. In addition, P29 blocked GC cell transformation from the G1/G0 phase to the S phase and weakened the invasive capability of GC cells. In this paper, we present a novel FGF2 inhibitor that could exert improved anticancer effect in GC in vitro.

A major goal of modern protein chemistry is to create new proteins with different functions. One approach is to amalgamate secondary and tertiary structures from different proteins. This is difficult for several reasons, not the least of which is the fact that the junctions between secondary and tertiary structures are not degenerate and usually affect the function and folding of the entire complex. Here, we offer a solution to this problem by coupling a large combinatorial library of about 10 7 different N- and C-terminal junctions to a powerful system that selects for function. Using this approach, the entire Leptin and follicle-stimulating hormone (FSH) were inserted into an antibody. Complexes with full retention of function in vivo and in vitro, although rare, were found easily by using an autocrine selection system to search for hormonal activity. Such large diversity systems, when coupled to robust selection systems, should enable construction of novel therapeutic proteins.

Fibroblast growth factor 2 (FGF2) plays a critical role in tumorigenesis and progression of solid tumor and is upregulated in gastric carcinoma serum. Therefore, it is regarded as a potential therapeutic target of human gastric cancer. Suppression of bioactivities of FGF2 may contribute to human gastric cancer therapy. Herein, we obtained a novel FGF2-binding peptide derivative (named P32), which originated from a previously isolated P7 peptide with poor stability. We proved that P32, which had a half-life in human plasma up to 12 h, enhanced stability and exerted strong inhibitory effect on FGF2-induced cell proliferation and invasion in human gastric cancer cell lines. Further investigations revealed that the underlying anti-proliferation mechanisms of P32 in vitro included arresting FGF2-stimulated cells at the G0/G1 phase and reducing the activation of AKT and Erk1/2 cascades. The FGF2-binding peptide derivative P32 has improved stability, is relatively safe, and may have therapeutic potential in FGF2-driven gastric cancer.

Some fibroblast growth factors (FGFs) play a critical role in tumorigenesis and progression. Among them, FGF2 was highly expressed in some tumors, and antagonists binding to FGF2 can suppress the growth of tumor cells. Therefore, FGF2 has been considered as an important target in cancer therapy. In this study, we identified a novel FGF2-binding short peptide (P8, PLLQATAGGGS-NH2) using phage display technology and alanine scanning. The P8 peptide suppressed FGF2-induced proliferation with no cytotoxic effect on cells, arrested the cycle at the G0/G1 phase in B16-F10 cells, and downregulated the activation of fibroblast growth factor receptor substrate 2α (FRS2α)/ERK cascade in B16-F10, NIH-H460, and SGC-7901 cells. Besides, P8 peptide can also inhibit the phosphorylation of FRS2α stimulated by FGF1 and KGF2. These implied that P8 peptide may develop as a multi-target antagonist peptide contributing to tumor treatment.