Photothermal therapy (PTT) offers many advantages such as high efficiency and minimal invasiveness, but clinical adoption of PTT nanoagents have been stifled by unresolved concerns such as the ...biodegradability as well as long-term toxicity. Herein, poly (lactic-co-glycolic acid) (PLGA) loaded with black phosphorus quantum dots (BPQDs) is processed by an emulsion method to produce biodegradable BPQDs/PLGA nanospheres. The hydrophobic PLGA not only isolates the interior BPQDs from oxygen and water to enhance the photothermal stability, but also control the degradation rate of the BPQDs. The in vitro and in vivo experiments demonstrate that the BPQDs/PLGA nanospheres have inappreciable toxicity and good biocompatibility, and possess excellent PTT efficiency and tumour targeting ability as evidenced by highly efficient tumour ablation under near infrared (NIR) laser illumination. These BP-based nanospheres combine biodegradability and biocompatibility with high PTT efficiency, thus promising high clinical potential.
Although phosphorene has attracted much attention in electronics and optoelectronics as a new type of two‐dimensional material, in‐depth investigations and applications have been limited by the ...current synthesis techniques. Herein, a basic N‐methyl‐2‐pyrrolidone (NMP) liquid exfoliation method is described to produce phosphorene with excellent water stability, controllable size and layer number, as well as in high yield. Phosphorene samples composed of one to four layers exhibit layer‐dependent Raman scattering characteristics thus providing a fast and efficient means for the in situ determination of the thickness (layer number) of phosphorene. The linear and nonlinear ultrafast absorption behavior of the as‐exfoliated phosphorene is investigated systematically by UV–vis–NIR absorption and Z‐scan measurements. By taking advantage of their unique nonlinear absorption, ultrashort pulse generation applicable to optical saturable absorbers is demonstrated. In addition to a unique fabrication technique, our work also reveals the large potential of phosphorene in ultrafast photonics.
A basic N‐methyl‐2‐pyrrolidone liquid exfoliation method is described to produce phosphorene with an excellent water stability, controllable size and layer number, as well as in a high yield. Phosphorene with one to four layers exhibits layer‐dependent Raman scattering characteristics thus providing a fast and efficient means for the in situ determination of the thickness of phosphorene.
Black phosphorus quantum dots (BPQDs) were synthesized using a liquid exfoliation method that combined probe sonication and bath sonication. With a lateral size of approximately 2.6 nm and a ...thickness of about 1.5 nm, the ultrasmall BPQDs exhibited an excellent NIR photothermal performance with a large extinction coefficient of 14.8 Lg−1 cm−1 at 808 nm, a photothermal conversion efficiency of 28.4 %, as well as good photostability. After PEG conjugation, the BPQDs showed enhanced stability in physiological medium, and there was no observable toxicity to different types of cells. NIR photoexcitation of the BPQDs in the presence of C6 and MCF7 cancer cells led to significant cell death, suggesting that the nanoparticles have large potential as photothermal agents.
A liquid exfoliation method based on a combination of probe sonication and bath sonication was adopted to synthesize black phosphorus quantum dots (BPQDs). These displayed a high extinction coefficient of 14.8 Lg−1 cm−1, a photothermal conversion efficiency of 28.4 %, and good biocompatibility, and can thus be used as highly effective photothermal agents for cancer therapy.
Photothermal therapy (PTT) is a fledgling therapeutic strategy for cancer treatment with minimal invasiveness but clinical adoption has been stifled by concerns such as insufficient biodegradability ...of the PTT agents and lack of an efficient delivery system. Here, black phosphorus (BP) nanosheets are incorporated with a thermosensitive hydrogel poly(d,l‐lactide)‐poly(ethylene glycol)‐poly(d,l‐lactide) (PDLLA‐PEG‐PDLLA: PLEL) to produce a new PTT system for postoperative treatment of cancer. The BP@PLEL hydrogel exhibits excellent near infrared (NIR) photothermal performance and a rapid NIR‐induced sol–gel transition as well as good biodegradability and biocompatibility in vitro and in vivo. Based on these merits, an in vivo PTT postoperative treatment strategy is established. Under NIR irradiation, the sprayed BP@PLEL hydrogel enables rapid gelation forming a gelled membrane on wounds and offers high PTT efficacy to eliminate residual tumor tissues after tumor removal surgery. Furthermore, the good photothermal antibacterial performance prevents infection and this efficient and biodegradable PTT system is very promising in postoperative treatment of cancer.
A sprayable and biodegradable photothermal therapy (PTT) system composed of a thermosensitive hydrogel incorporated with black phosphorus (BP) nanosheets is presented for post‐surgical treatment of cancer. The obtained hydrogel enables rapid gelation and offers high PTT efficacy to eliminate residual tumor after surgery. This efficient and biodegradable PTT system is very promising in the postoperative treatment of cancer.
The photochemical activity of black phosphorus (BP) in near‐infrared (NIR) light controlled in situ biomineralization is investigated. Owing to the excellent NIR absorption, irradiation with NIR ...light not only promotes degradation of BP into PO43−, but also enhances the chemical activity to accelerate the reaction between PO43− and Ca2+ and promote in situ biomineralization. Mineralization of hydrogels is demonstrated by the preparation of BP incorporated hydrogel (BP@Hydrogel) which delivers greatly improved biomineralization performance under NIR illumination. The biomineralization process which can be controlled by modulating the light irradiation time and location has a high potential in controlling the mechanical properties and osteoinductive ability in tissue engineering. This study also provides insights into the degradation, photochemical activity, and new biological/biomedical applications of BP.
Photochemical activity of black phosphorus (BP) for controlled in situ biomineralization is investigated. Near infrared (NIR) light can promote the degradation of BP and enhance their chemical activity to accelerate the mineralization process. BP@Hydrogel with NIR irradiation exhibit greatly improved biomineralization and can be controlled by modulating the irradiation time and location, thus promising high potential in bioengineering.
The nonlinear optical property of topological insulator bismuth selenide (Bi2Se3) is found to be well-tailored through ion irradiation by intentionally introducing defects. The increase of the ...optical modulation depth sensitively depends on the careful selection of the irradiation condition. By implementing the ion irradiated Bi2Se3 film as an optical saturable absorber device for the Q-switched wave-guide laser, an enhanced laser performance has been obtained including narrower pulse duration and higher peak power. Our work provides a new approach of tailoring the nonlinear optical properties of materials through ion irradiation, a well-developed chip-technology, which could find wider applicability to other layered two-dimensional materials beyond topological insulators, such as graphene, MoS2, black phosphours etc.
Head and neck cancer is the sixth most common cancer in the world, with more than 300,000 deaths attributed to the disease annually. Aggressive surgical resection often with adjuvant chemoradiation ...is the cornerstone of treatment. However, the necessary chemoradiation treatment can result in collateral damage to adjacent vital structures causing a profound impact on quality of life. Here, we present a novel polymer of poly(lactic-co-glycolic) acid and polyvinyl alcohol that can serve as a versatile multidrug delivery platform as well as for detection on cross-sectional imaging while functioning as a fiduciary marker for postoperative radiotherapy and radiotherapeutic dosing. In a mouse xenograft model, the dual-layered polymer composed of calcium carbonate/thymoquinone was used for both polymer localization and narrow-field infusion of a natural therapeutic compound. A similar approach can be applied in the treatment of head and neck cancer patients, where immunotherapy and traditional chemotherapy can be delivered simultaneously with independent release kinetics.
The structural evolution and nanoscale properties of PLLA nanofiber during the early quenching period in a thermally induced phase separation process have been investigated. The PLLA/THF solution was ...prepared at 60°C and quenched in a −24°C refrigerator for different times to become a gel. The morphology, phase transition, crystallization behavior, hydrophobicity, variation of chain conformation and adhesion force were studied by using SEM, WAXD, ATR-FTIR, DSC, contact angle measurement, AFM and force spectroscopy measurements. The initial phase separation resulted in an amorphous gel with the condensation of nanoparticles, followed by the nucleation of PLLA crystals. The α-form crystal appeared after quenching for 1min, corresponding to a gel temperature around 15°C. After quenching for sufficient time (longer than 3min) and the gel temperature decreasing to below 0°C, a nanofibrous architecture was formed with a limited disorder α′-form crystal. With the extending of the gelation time, the degree of crystallinity of the matrix increased and conformational transformation of the polymer chains proceeded with more closely packed polymer segments that restricted the backbone COC vibration and strengthened interchain interaction of the CO bonds. The surface morphology and structural evolution led to the increase in the hydrophobicity as well as nanoscale mechanical property of the nanofibers. AFM and force spectroscopy measurements of 2-D samples on the glass slide showed that the nanofiber formation seemed to initiate from a central nuclei and grew radially outward and larger fibers were assembled laterally with a bunch of thinner nanofibers. The adhesion force increased with the gelation time which suggested that the structural evolution of PLLA chains conformation and the chain packing has a direct functional consequence in the nanoscale mechanical property.
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