Neoantigen vaccination augments antitumor effects of anti-PD-1 on mouse hepatocellular carcinoma.

Immune checkpoint inhibitors are groundbreaking resources for cancer therapy. However, only a few patients with hepatocellular carcinoma (HCC) have shown positive responses to anti-PD-1 therapy. Neoantigens are sequence-altered proteins resulting from somatic mutations in cancer. This study identified the neoantigens of Hep-55.1C and Dt81 Hepa1-6 HCCs by comparing their whole exome sequences with those of a normal C57BL/6 mouse liver. Immunogenic long peptides were pooled as peptide vaccines. The vaccination elicited tumor-reactive immune responses in C57BL/6 mice, as demonstrated by IFN-γ ELISPOT and an in vitro killing assay of splenocytes. In the treatment of three mouse HCC models, combined neoantigen vaccination and anti-PD-1 resulted in more significant tumor regression than monotherapies. Flow cytometry of the tumor-infiltrating lymphocytes showed decreased Treg cells and monocytic myeloid-derived suppressor cells, increased CD8+ T cells, enhanced granzyme B expression, and reduced exhaustion-related markers PD-1 and Lag-3 on CD8+ T cells in the combination group. These findings provide a strong rationale for conducting clinical studies of using neoantigen vaccination in combination with anti-PD-1 to treat patients with HCC.

Therapeutic Effects of Anti-PD1 Immunotherapy on Hepatocellular Carcinoma Under Administration of Tacrolimus.

BACKGROUND: Liver transplantation (LT) is the treatment of choice for patients with hepatocellular carcinoma (HCC). Recurrence of HCC after LT occurs in 10% to 20% of cases. Preclinical studies to evaluate immune checkpoint inhibitors in conjunction with immunosuppressant treatment in transplant recipients have been lacking. Here, we evaluated the efficacy, safety, and mechanism of programmed cell death-1 (PD1) blockade under tacrolimus treatment in transplant recipients. METHODS: We used a murine allogeneic skin transplantation model and murine syngeneic subcutaneous and orthotopic HCC models and measured the tumor volume and the change in tumor-infiltrating lymphocytes under PD1 blockade and tacrolimus treatment. RESULTS: Tacrolimus treatment prolonged allograft survival in the allogeneic transplantation model and enhanced tumor growth in both subcutaneous and orthotopic HCC models. PD1 blockade suppressed tumor growth and lung metastasis in correlation with the number of infiltrating CD8 + T cells. Under tacrolimus treatment, PD1 blockade still resulted in an antitumor effect accompanied by a significant increase in tumor-infiltrating CD8 + T cells, natural killer cells, dendritic cells, and natural killer T cells. Tacrolimus treatment rescued the acceleration of transplant rejection induced by PD1 blockade in the allogeneic transplantation model. CONCLUSIONS: Our data suggest that treatment with high-dose tacrolimus in conjunction with PD1 blockade has an antitumor effect and reduces transplant rejection in mouse models of allograft skin transplantation and HCC. Thus, these results suggest that a clinical trial of PD1 inhibitors for HCC in LT merits consideration.

Low-Voltage Actuator with Bilayer Structure for Various Biomimetic Locomotions.

Composites based on a shape-memory polymer doped with conductive particles are considered as soft actuators for artificial muscles and robots. Low-voltage actuating is expected to reduce equipment requirement and safety hazards, which requires a highly conductive particle content but weakens the reversible deformation. The spatial distribution of the conductive particle is key to decreasing the actuating voltage and maintaining the reversible deformation. Herein, an approach of fabricating a low-voltage actuator that can perform various biomimetic locomotions by spraying and hot pressing is reported. Carbon nanotubes (CNTs) are enriched inside the surface layer of poly(ethylene-co-vinyl acetate) (EVA) to form a high-density conductive network without degradation of the reversible deformation. The bilayer CNT/EVA actuator exhibits a reversible transformation of more than 10% even with 100 cycles, which requires an applied voltage of just 15 V. Taking advantage of the reprogrammability of the CNT/EVA actuator and reversible shift between the different shapes, different biomimetic locomotions (sample actuator, gripper, and walking robot) are demonstrated without any additional mechanical components. A scheme combining the electrical properties and the shape-memory effect provides a versatile strategy to fabricate low-voltage-actuated polymeric actuators, providing inspiration in the development of electrical soft actuators and biomimetic devices.

Durably Ductile, Transparent Polystyrene Based on Extensional Stress-Induced Rejuvenation Stabilized by Styrene-Butadiene Block Copolymer Nanofibrils.

The glassy polymer of polystyrene (PS) enjoys a good reputation as a promising optical material; however, the inherent brittleness hinders its further applications. Conventional toughening methods are realized based on the premise of a sacrifice in transparency and stiffness. In this work, we found an unprecedented strategy to address these obstacles by combining extensional stress-induced ductility and suppressing physical aging. PS-based film with a high stiffness, long-term ductility, and excellent transparency is achieved by introducing a styrene-butadiene block copolymer into the PS matrix and subsequently annealing stretched. A nanofibrillar structure of the polybutadiene (PB) phase is formulated surrounded by a PS matrix, and thus, the elongation at break enhances from 3.1% up to 86.8%, accompanying the yield strength enhanced from 25.5 to 62.2 MPa. More significantly, compared with neat PS, these films survive from physical aging and persistent ductility over time. The morphology deformation induced by stress makes an obvious contribution to the improvement of transparency. Investigating the dynamics of chain segments indicates that the incorporation of the copolymer can restrict rearrangement and local relaxation to the PS chain. This work could pave a potential route toward high-performance PS and might be transferable to other glassy polymers with a fragile character.

In Vitro Bioactivity and Antibacterial Activity of Strontium-, Magnesium-, and Zinc-Multidoped Hydroxyapatite Porous Coatings Applied via Atmospheric Plasma Spraying.

The beneficial effects of Sr- and Mg-doped hydroxyapatite (HAp) on osteoblast proliferation and bone regeneration have been investigated in the past, and the antibacterial ability of Zn ions is well known. However, HAp coatings doped with these three elements via thermal spraying have not yet been investigated. In this study, HAp powder was synthesized at different pH values (4, 6, 8, and 10) and calcined at different temperatures (200, 400, 600, 800, and 1000 °C) to obtain HAp with the highest purity. Subsequently, strontium-, magnesium-, and zinc-doped HAp powders were synthesized at the optimal pH value and calcination temperature. The HAp powder was then coated onto Ti disks using atmospheric plasma spraying (APS) or vapor-induced pore-forming atmospheric plasma spraying (VIPF-APS) techniques at different working currents (350, 400, and 450 A) and spraying distances (10 and 15 cm). X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy equipped with energy-dispersive spectroscopy were used for material characterization to determine the optimal parameters. With these optimal coating parameters, HAp, Zn-HAp, SrMg-HAp, and ZnSrMg-HAp powders were deposited onto the Ti disks using VIPF-APS and named HAp-Ti, Zn-HAp-Ti, SrMg-HAp-Ti, and ZnSrMg-HAp-Ti, respectively. The in vitro bioactivity of these four groups was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and alkaline phosphatase (ALPase) activity assay. Besides, the antibacterial activities against Prevotella nigrescens, Porphyromonas gingivalis, and Fusobacterium nucleatum were assessed. The results showed that the purity of HAp synthesized at pH 10 and 800 °C was 98.40%. A porous coating without cracks was obtained at a 10 cm spraying distance and 400 A working current using VIPF-APS. SrMg-HAp-Ti and ZnSrMg-HAp-Ti resulted in higher osteoblast proliferation and ALPase activity than the control. Moreover, both Zn-HAp-Ti and ZnSrMg-HAp-Ti exhibited antibacterial activity against the three bacteria. Therefore, ZnSrMg-HAp has potential as a coating for biomedical materials due to its ability to reduce bacterial infection and enhance osseointegration.

Structure-guided design, generation, and biofunction of PEGylated fibroblast growth factor 2 variants for wound healing.

Fibroblast growth factor 2 (FGF2) plays an important role in multiple physiological functions such as tissue repair. However, FGF2 has a short half-life in vivo due to protease degradation, thus limiting its clinical application. Traditional PEGylation has typically focused on the N-terminal α-amino group of FGF2. These modifications do not consider potential effects on protein function or structure, and sometimes lead to decreased bioactivity. In this study, we generated three PEGylated FGF2 variants based on the structure of the FGF2-FGFR-heparin ternary complex via gene mutation and PEGylation, and investigated the effects of these PEGylated sites on protein stability and bioactivity. Compared with native FGF2, all PEG-FGF2 conjugates exhibited significantly improved stability. Conjugates PEGylated at a site separated from both binding regions more effectively promoted proliferation, migration and angiogenesis than FGF2 in vitro, and exhibited excellent wound healing activity in vivo, making these conjugates potential therapeutic candidates for wound healing. Computer-assisted modification based on structure reveals the detailed structural characteristics of proteins, allowing efficient protein modification for improved stability and activity. This structure-guided PEGylation offers a more reliable modification strategy and should be applied for the rational design of protein-based therapeutics.

Engineering Antifouling and Antibacterial Stainless Steel for Orthodontic Appliances through Layer-by-Layer Deposition of Nanocomposite Coatings.

In this study, a nanocomposite coating composed of polydopamine, functionalized poly(3,4-ethylenedioxythiophene) (PEDOT), and silver nanoparticles (AgNPs) was synthesized through layer-by-layer deposition. Biomimitic polydopamine and hydroxyl-functionalized PEDOT were used to enhance the adhesion strength. The deposition of PEDOT functionalized with zwitterionic phosphorylcholine can contribute to the antifouling property. After immersion in the AgNO3 solution, Ag+ ions were adsorbed on PEDOT films and further reduced to form AgNPs spontaneously, which conferred antibacterial properties on these nanocomposite films. Escherichia coli and Streptococcus mutans were chosen to represent two common Gram-negative and Gram-positive oral pathogens. We further conducted inductively coupled plasma mass spectrometry to confirm that the Ag+ ions released from these nanocomposite films did not exert adverse effects on the human body. These results suggested that, when applied to stainless steel orthodontic appliances, these durable antifouling and antibacterial coatings may be useful for avoiding bacterial infection.

Enhancement of palladium-porphyrin room temperature phosphorescence by alkaline earth metal in deoxycholate aggregates solution.

Room temperature phosphorescence (RTP) of three palladium (Pd)-phorphyrins in air-saturated solution of sodium deoxycholate (NaDC) aggregates was measured. RTP of Pd-meso-tetrakis (4-carboxyphenyl) porphyrin (Pd-TCPP) was obviously enhanced in NaDC-aggregates mediated by alkaline earth metal (AEM). Under the same experimental conditions, Ca(2+), Ba(2+) and Mg(2+) induced 200, 90 and 24 times greater enhancement in RTP of Pd-TCPP, respectively. It is ascribed to form the complex of NaDC-aggregate/AEM/Pd-TCPP in the system. The positively charged AEM has a strong capability of co-ordination with negatively charged carboxyl groups of NaDC and Pd-TCPP. The phosphor Pd-TCPP is confined in rigid NaDC-aggregates/AEM system by the coordination which decreases the probability of collision of phosphor with quenchers such as dissolved oxygen molecules and prolongs the lifetime of the phosphor on the triplet state. Long excited-state lifetimes resulted in great enhancement of Pd-TCPP phosphorescence. Observations by optical microscope showed that specific fan-like structures of NaDC were formed under the influence of AEM. Surface tension measurements supported a close interaction between Ca(2+) ions and anion aggregates of NaDC with 1:1 stoichiometric ratio. Due to its outstanding RTP behavior in NaDC-aggregates induced by Ca(2+), Pd-TCPP was used as a RTP probe to detect bovine serum albumin (BSA). A broad linear range from 1.0 × 10(-9) to 9.0 × 10(-7) g mL(-1) was obtained. Detection limit is 2.6 × 10(-11) g mL(-1), the relative standard deviation (n = 6) is 2.3% for 2.0 × 10(-9) g mL(-1) BSA.

H-aggregation of cationic palladium-porphyrin as a function of anionic surfactant studied using phosphorescence, absorption and RLS spectra.

Room temperature phosphorescence (RTP) was used as a useful analytical tool to investigate the interaction behavior between tetracationic meso-tetrakis (4-trimethylaminophenyl) porphyrin palladium (Pd-TAPP) and anionic sodium dodecyl sulfate (SDS). UV-vis absorption and resonance light scattering (RLS) were further applied to characterize the system. It was presumably suggested that nonspecific self-aggregates among porphyrins formed considering the relatively high concentration of Pd-TAPP. Furthermore, Pd-TAPP changed from free monomer/nonspecific aggregate to H-aggregate and then to out-micellized monomer/nonspecific aggregate as a function of SDS concentration. The fact that RTP signal enhanced obviously and excitation spectrum was blue-shifted by 1580cm(-1) in energy with respect to energy of free Pd-TAPP monomer demonstrated that 1:4 electrostatic interaction between Pd-TAPP and SDS led to the formation of the premicellar porphyrin-surfactant H-aggregates. The RLS spectrum reviewed that the formed H-aggregates were multiple porphyrin units, and UV-vis spectra revealed that cationic groups of monomers/nonspecific aggregates of Pd-TAPP were electrostatically attracted in favor of the surface of anionic micelles but were not encapsulated within apolar regions of SDS micelles when the concentration of SDS was above its critical micelle concentration (CMC).