Parallel near-field photolithography with metal-coated elastomeric masks.

Developing a cost-effective nanolithography strategy that enables the production of subwavelength features with various shapes over large areas is a long-standing goal in the nanotechnology community. Herein, an inexpensive nanolithographic technique that combines the wafer-scale production capability of photolithography with the subwavelength feature size controllability of near-field photolithography was developed to fabricate centimeter-scale up to wafer-scale sub-100-nm variously shaped nanopatterns on surfaces. The wafer-scale elastomeric trench-based photomasks with subwavelength apertures created at the apexes were compatible with mask aligners, allowing for the production of wafer-scale subwavelength nanopatterns with adjustable feature sizes, shapes, and periodicities. The smallest feature sizes of 50 and 80 nm were achieved on positive tone and negative tone photoresist surfaces, respectively, which could be ascribed to a near-field optical effect. The fabricated centimeter-scale nanopatterns were functionalized to study cell-matrix adhesion and migration. Compared to currently developed nanolithographic methods that approach similar functionalities, this facile nanolithographic strategy combines the merits of low cost, subwavelength feature size, high throughput, and varied feature shapes, making it an affordable approach to be used in academic research for researchers at most institutions.

Polysarcosine as PEG Alternative for Enhanced Camptothecin-Induced Cancer Immunogenic Cell Death.

Nanomedicine-enhanced immunogenic cell death (ICD) has attracted considerable attention for its great potential in cancer treatment. Even though polyethylene glycol (PEG) is widely recognized as the gold standard for surface modification of nanomedicines, some shortcomings associated with this PEGylation, such as hindered cell endocytosis and accelerated blood clearance phenomenon, have been revealed in recent years. Notably, polysarcosine (PSar) as a highly biocompatible polymer can be finely synthesized by mild ring-opening polymerization (ROP) of sarcosine N-carboxyanhydrides (Sar-NCAs) and exhibit great potential as an alternative to PEG. In this article, PSar-b-polycamptothecin block copolymers are synthesized by sequential ROP of camptothecin-based NCAs (CPT-NCAs) and Sar-NCAs. Then, the detailed and systematic comparison between PEGylation and PSarylation against the 4T1 tumor model indicates that PSar decoration can facilitate the cell endocytosis, greatly enhancing the ICD effects and antitumor efficacy. Therefore, it is believed that this well-developed PSarylation technique will achieve effective and precise cancer treatment in the near future.

Development of magnesium hydroxide-doped nanofibrous spheres for repairing infected skin wounds.

The healing of skin wounds is a continuous and coordinated process, typically accompanied by microbial colonization and growth. This may result in wound infection and subsequent delay in wound healing. Therefore, it is of particular importance to inhibit the growth of microorganisms in the wound environment. In this study, magnesium hydroxide-doped polycaprolactone (PCL/MH) nanofibrous spheres were fabricated by electrospinning and electrospray techniques to investigate their effects on infected wound healing. The prepared PCL/MH nanofibrous spheres had good porous structure and biocompatibility, providing a favorable environment for the delivery and proliferation of adipose stem cells. The incorporation of MH significantly enhanced the antimicrobial properties of the spheres, in particular, the inhibition of the growth of S. aureus and E. coli. We showed that such PCL/MH nanofibrous spheres had good antimicrobial properties and effectively promoted the regeneration of infected wound tissues, which provided a new idea for the clinical treatment of infected wounds.

Single Polylactic Acid Nanowire for Highly Sensitive and Multifunctional Optical Biosensing.

Nanowire-based optical biosensors with high sensitivity are highly desired for the detection of biological microenvironments and analysis of cellular processes. However, the current nanowire biosensors are mostly fabricated with metal and semiconductor materials, which are not suitable for long-term use in biological environments due to their incompatible and nondegradable properties. Biosensors based on biofriendly materials (e.g., spider silk) often do not have high enough sensitivity due to high losses or micron sizes. Here, polylactic acid (PLA), a polymer with high optical transparency, good biocompatibility, biodegradability, and flexibility, is used to fabricate nanowires using a directly drawing method for the first time. Because of the strong evanescent wave and abundant carboxyl groups on the surface of nanowires, an ultralow concentration sensing of cytochrome c is achieved with a limit of detection of 1.38 × 10-17 M, which is much lower than other detection results using semiconductor/metal-based nanosensors (10-6 to 10-12 M). On this basis, a label-free and real-time monitoring of cell apoptosis is realized. In addition, by doping quantum dots, the functionalized PLA nanowires can also sense a change in pH. These results are suggestive of the potential for PLA nanowires applied in multifunctional biosensing and biodetection, pushing forward the photomedicine field.

Transferrin-Decorated Protein-Lipid Hybrid Nanoparticle Efficiently Delivers Cisplatin and Docetaxel for Targeted Lung Cancer Treatment.

PURPOSE: Non-small cell lung cancer (NSCLC) therapy faces the barriers including drug resistance. A transferrin-functionalized protein-lipid hybrid nanoparticle (PLHN) was designed loading both cisplatin (CIS) and docetaxel (DTX) for the lung cancer treatment. METHODS: CIS and DTX were loaded into the hybrid nanoparticle and then decorated with transferrin (Tf). The Tf-functionalized protein-lipid hybrid nanoparticle (Tf-CIS/DTX-PLHN) was investigated by determining the release behavior, cytotoxicity in vitro, and anticancer efficiency in vivo. RESULTS: Tf-CIS/DTX-PLHN showed a nano-size of 189.5 ± 5.9 nm, and a surface tested to be -16.9 ± 2.1 mV. Tf-CIS/DTX-PLHN exhibited obviously better antitumor ability in vitro and in vivo compared with the non Tf contained CIS and DTX co-loaded lipid nanoparticles (CIS/DTX-LN), single drug loaded nanoparticles, and free drugs. CONCLUSION: Since remarkable enhanced efficiency of Tf and synergistic effect of the drugs, it could inhibit the lung tumor growth and help with the lung cancer treatment.

Self-repair capability of surgically created incisions in TMJ disc: an experimental study on goats.

This study was to investigate whether surgically created incisions in discs at different sizes would heal spontaneously. Thirty mature goats were randomly divided into group A (1 mm), group B (3 mm) and group C (5 mm) according to the length of incision on the discs. Five animals in each group were sacrificed at 3 and 6 months postoperatively. The disc and condyle were evaluated by gross, histological and immunohistochemistry examinations. 1-mm discal incisions healed spontaneously with nearly normal gross and histological appearance at 6 months postoperatively, while 3-mm and 5-mm discal incisions failed to heal. Degenerative changes were observed in the fibrocartilage in both 3-mm and 5-mm incision groups, with a greater extent in the 5-mm group. Our results suggested that the TMJ disc of goat has limited self-repair capability to damage, which will be useful for making pre-surgical decisions related to the size and healing period of TMJ disc perforations.

Retrospective comparison of autogenous cosotochondral graft and coronoid process graft in the management of unilateral ankylosis of the temporomandibular joint in adults.

We retrospectively compared the clinical outcomes of autogenous coronoid process grafts (n=32) and costochondral grafts (n=28) in condylar reconstruction for the treatment of unilateral ankylosis of the temporomandibular joint (TMJ) in adults. Preoperative and postoperative assessments included diet scores, cone-beam computed tomography (CT), maximal interincisal opening, lateral excursion, and mandibular deviation on opening the mouth. There were no significant differences between the 2 groups in the measurements before and after the operation with respect to incisal opening, lateral excursion, mandibular deviation, diet scores, or recurrence rate, but in both the postoperative incisal opening, lateral excursion, and diet scores had improved significantly compared with preoperatively. After costochondral graft 3 patients developed intraoperative plural tears, and 6 had temporary pain at the donor site. The frontal branch of the facial nerve was temporarily affected in 5 patients after costochondral graft and 3 after coronoid process grafts, all of which recovered in 3-6 months. There was no recurrence after coronoid process grafting, and one after costochondral grafting. The clinical outcomes in both groups were satisfactory and comparable. Autogenous coronoid process grafting may therefore be a good alternative for condylar reconstruction in patients with ankylosis of the TMJ.