Two‐dimensional Bi2O2Se quantum dots (QDs) are synthesized by a facile top‐down approach in article number 1905208 by Yue Chen, Zhenyou Jiang, Jundong Shao, an co‐workers. Boasting large photothermal ...conversion efficiency and excellent photoacoustic performance as well as suitable biodegradability, the Bi2O2Se QDs facilitate photoacoustic imaging of whole tumors in photothermal cancer therapy. The semiconducting QDs are promising as a near‐infrared‐triggered theranostic agent in cancer therapy.
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► Early stage evolution of structure and nanoscale property in TIPS process. ► Nanofiber initiate from crystalline grains and assembled with a bunch of thinner ones. ► Crystallization ...result in more chain entanglement and decrease chain mobility. ► Chain packing has a direct functional consequence in the nanomechnical properties. ► Nanofiber have more significant plastic deformation and creep.
The surface morphology, crystalline structure and nanomechanical properties of poly(l-lactide) (PLLA) samples prepared via thermally induced phase separation (TIPS) process have been investigated by scanning electron microscopy (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), wide-angle X-ray diffraction (WAXD), atomic force microscopy (AFM), force spectroscopy and nanoindentation. Typical nanofibrous scaffold was obtained at −24°C (NF sample) while a denser matrix with some plateletlike structure was obtained at 15°C (PL sample). The NF sample has a higher crystallinity with α′-form crystals while the PL sample has α-form crystals embedded in a largely amorphous matrix. The two kinds of samples have differences in the chain conformation with a more restricted backbone vibration and stiffened segmental motion in NF samples. The NF samples have a higher adhesion force although both samples showed a heterogeneous distribution of adhesion force on the surface based on force spectroscopy analysis. The alternating distribution of domains with higher and lower adhesion force exhibited a banded pattern on PLLA nanofibre. This pattern is proposed to reflect the distribution of crystal-rich and amorphous-rich domains in the semicrystalline samples. AFM-based nanoindentation test indicated that the nanofibrous NF samples can have more significant plastic deformation and creep than the largely amorphous PL samples. The sliding of the crystal-rich domains along the fibrils would account for this increased plasticity of the nanofiber.
The structural evolution and the corresponding biodegradability and biological property of PLLA porous scaffolds during the early quenching period in a thermally induced phase separation process have ...been investigated. The morphology, crystallization behavior, chemical structure, surface property, hydrophobicity, biodegradability and biological property were studied by using SEM, WAXD, XPS, contact angle measurement, AFM, hydrolytic degradation and cell culture experiments. The initial phase separation resulted in an amorphous gel with the condensation of patches of amorphous precipitates, followed by the nucleation of PLLA crystals. With extending the gelation process, a microporous structure was formed. A temperature dependent phase behavior during the early quenching period has been observed. Along with the increase in the degree of crystallinity, structural transformation of the polymer toward a more ordered and compact state proceeded with the extending of the gelation time. The possible surface segregation of the methyl groups was confirmed by XPS analysis which may have certain effect on the increase of water contact angle. The evolution of architecture, crystallinity, chemical structure, surface property and the polymer chain packing mode, etc, during the early quenching period, has a direct functional consequence in the hydrophobicity, biodegradability as well as biological property.
•Ultrasmall biodegradable nitride MXene quantum dots (Ti2N QDs) are prepared.•Ti2N QDs exhibit excellent PA and PTT performance in both NIR-I/II biowindows.•Ti2N QDs show appropriate degradation rate ...and excretion rate from the body.•The prepared QDs are promising for precision cancer treatment.
As a prominent member of two dimensional (2D) materials, MXenes have shown encouraging photophysical properties and so there is highly desirability to explore their phototherapeutic potential in cancer. Herein, we demonstrate a facile top-down strategy for the synthesis of nitride-based MXene, titanium nitride quantum dots (Ti2N QDs) in solution. With a size of around 5 nm, the obtained Ti2N QDs exhibit extraordinarily high photothermal conversion efficiency under laser irradiation in both first and second near-infrared (NIR) biowindows (NIR-I, 808 nm, 48.62%; and NIR-II, 1064 nm, 45.51%). In vitro and in vivo assessments demonstrate that the Ti2N QDs possess excellent biocompatibility, photoacoustic (PA) effect, and photothermal therapy (PTT) efficiency. Moreover, the Ti2N QDs showing obvious aggregation in tumors after 4 h post-injection, which enables facilitate PA imaging-guided PTT in both NIR-I/II biowindows without noticeable toxicity. Encouragingly, the Ti2N QDs with appropriate degradation property also show an applicable excretion rate from the body in vivo, which ensures sufficient stability in circulation to accomplish therapeutics roles and then can be smoothly discharged from the body after that. These results indicate the high potential of biodegradable Ti2N QDs in PA imaging-guided PTT in both NIR-I/II biowindows for precision cancer treatment.
In breast cancer chemophotothermal therapy, it is a great challenge for the development of multifunctional nanoagents for precision targeting and the effective treatment of tumors, especially for ...metastasis. Herein, we successfully design and synthesize a multifunctional black phosphorus (BP)-based nanoagent, BP/DTX@PLGA, to address this challenge. In this composite nanoagent, BP quantum dots (BPQDs) are loaded into poly(lactic-co-glycolic acid) (PLGA) with additional conjugation of a chemotherapeutic agent, docetaxel (DTX). The in vivo distribution results demonstrate that BP/DTX@PLGA shows striking tropism for targeting both primary tumors and lung metastatic tumors. Moreover, BP/DTX@PLGA exhibits outstanding controllable chemophotothermal combinatory therapeutics, which dramatically improves the efficacy of photothermal tumor ablation when combined with near-light irradiation. Mechanistically, accelerated DTX release from the nanocomplex upon heating and thermal treatment per se synergistically incurs apoptosis-dependent cell death, resulting in the elimination of lung metastasis. Meanwhile, in vitro and in vivo results further confirm that BP/DTX@PLGA possesses good biocompatibility. This study provides a promising BP-based multimodal nanoagent to constrain cancer metastasis.
Topical therapy is a favored route for treating skin cancers, but remain many challenges, such as low delivery efficiency, limited tumor tissue penetration, and unsatisfactory blood circulation. ...Here, a self‐heating microneedle (MN) patch with multilevel structures, including a dissolvable base for rapid drug release, a degradable tip for sustained drug release, and a self‐heating substrate is described. The thermally enhanced drug release performance is validated through both in vitro and in vivo experiments. High tumor therapeutic efficacy can be achieved due to the rapid release of 5‐fluorouracil, while the sustained release of thymoquinone endows the MN patch with long‐term tumor inhibition ability. It is further demonstrated the feasibility of such an MN patch for in vivo topical therapy of cutaneous squamous cell carcinoma with high efficacy, low side effects, and long‐term inhibition of recurrence. This self‐heating MN patch holds great promise for potential clinical applications, especially for the treatment of skin cancers.
The development of a self‐heating multistage microneedle patch is reported. It presents a multilevel structure including a dissolvable base for rapid drug release (5‐FU/HA), a degradable tip for sustained drug release (thymoquinone/Poly(lactic‐co‐glycolic acid)), and a substrate filled with self‐heating material (Fe power mixture). Such self‐heating microneedle patch is very promising for the high‐efficient topical therapy of skin cancer.
In this paper, we propose a new shape memory polymer (SMP) composite with excellent near-infrared (NIR)-photoresponsive shape memory performance and biodegradability. The composite is fabricated by ...using piperazine-based polyurethane (PU) as thermo-responsive SMP incorporated with black-phosphorus (BP) sheets as NIR photothermal nanofillers. Under 808 nm light irradiation, the incorporated BP sheets with concentration of only 0.08 wt% enable rapid temperature increase over the glass temperature of PU and trigger the shape change of the composite with shape recovery rate of ∼100%. The in vitro and in vivo toxicity examinations demonstrate the good biocompatibility of the PU/BP composite, and it degrades naturally into non-toxic carbon dioxide and water from PU and non-toxic phosphate from BP. By implanting PU/BP columns into back subcutis and vagina of mice, they exhibit excellent shape memory activity to change their shape quickly under moderate 808 nm light irradiaiton. Such SMP composite enable the development of intelligent implantable devices, which can be easily controlled by the remote NIR light and degrade gradually after performing the designed functions in the body.
A titanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP, the BP after surface coordination exhibits ...excellent stability during dispersion in water and exposure to air for a long period of time, thereby significantly extending the lifetime and spurring broader application of BP.
A titanium sulfonate ligand was synthesized and used to coordinate with black phosphorus (BP). In contrast to the serious degradation observed in bare BP, the BP after surface coordination exhibited excellent stability during dispersion in water and exposure to air for a long period of time, significantly extending the lifetime and spurring broader applications of BP.
Poly(vinylpyrrolidone)-encapsulated Bi2 Se3 nanosheets with a thickness of 1.7 nm and diameter of 31.4 nm are prepared by a solution method. Possessing an extinction coefficient of 11.5 L g(-1) ...cm(-1) at 808 nm, the ultrathin Bi2 Se3 nanosheets boast a high photothermal conversion efficiency of 34.6% and excellent photoacoustic performance. After systemic administration, the Bi2 Se3 nanosheets with the proper size and surface properties accumulate passively in tumors enabling efficient photoacoustic imaging of the entire tumors to facilitate photothermal cancer therapy. In vivo biodistribution studies reveal that they are expelled from the body efficiently after 30 d. The ultrathin Bi2 Se3 nanosheets have large clinical potential as metabolizable near-infrared-triggered theranostic agents.
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