Covalent organic framework nanomedicines: Biocompatibility for advanced nanocarriers and cancer theranostics applications.

Nanomedicines for drug delivery and imaging-guided cancer therapy is a rapidly growing research area. The unique properties of nanomedicines have a massive potential in solving longstanding challenges of existing cancer drugs, such as poor localization at the tumor site, high drug doses and toxicity, recurrence, and poor immune response. However, inadequate biocompatibility restricts their potential in clinical translation. Therefore, advanced nanomaterials with high biocompatibility and enhanced therapeutic efficiency are highly desired to fast-track the clinical translation of nanomedicines. Intrinsic properties of nanoscale covalent organic frameworks (nCOFs), such as suitable size, modular pore geometry and porosity, and straightforward post-synthetic modification via simple organic transformations, make them incredibly attractive for future nanomedicines. The ability of COFs to disintegrate in a slightly acidic tumor microenvironment also gives them a competitive advantage in targeted delivery. This review summarizes recently published applications of COFs in drug delivery, photo-immuno therapy, sonodynamic therapy, photothermal therapy, chemotherapy, pyroptosis, and combination therapy. Herein we mainly focused on modifications of COFs to enhance their biocompatibility, efficacy and potential clinical translation. This review will provide the fundamental knowledge in designing biocompatible nCOFs-based nanomedicines and will help in the rapid development of cancer drug carriers and theranostics.

The complete mitochondrial genome of Aclees taiwanensis Kôno, 1933 (Coleoptera: Curculionidae).

We sequenced the complete mitochondrial genome of Aclees taiwanensis collected in Korea. The circular mitogenome of A. taiwanensis is 17,435 bp, longer than that of Aclees cribratus, and includes 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNAs, and a control region/D-loop. The AT ratio is 75.4%. Maximum-likelihood and Bayesian inference phylogenetic trees showed that A. taiwanensis was clustered with A. cribratus with full-support values for both trees.

Photopatternable Poly(dimethylsiloxane) (PDMS) for an Intrinsically Stretchable Organic Electrochemical Transistor.

Patterning elastomers is an essential process for the application of elastomers to stretchable bioelectric devices. In general, replication of a mold and laser ablation are used for patterning elastomers. However, these methods are inefficient and time consuming due to complex patterning procedures and a heat-induced curing mechanism. In this work, we developed a photopatternable elastomer called thiol-ene cross-linked poly(dimethylsiloxane) (TC-PDMS). TC-PDMS showed high-resolution patternability (∼100 µm) through a direct patterning process. It also had high stretchability (∼140%) and low Young's modulus (∼2.9 MPa) similar to conventional PDMS. To demonstrate its practicability in stretchable bioelectric devices, TC-PDMS was applied to a passivation layer of an intrinsically stretchable organic electrochemical transistor (OECT), which showed a low leakage current (∼20 µA) and a high transconductance (0.432 mS) at high strain (60%). The stretchable OECT was able to record electrocardiographic (ECG) signals from human skin, and the measured ECG signals exhibited a high signal-to-noise ratio of 12.2 dB.

Conformable microneedle pH sensors via the integration of two different siloxane polymers for mapping peripheral artery disease.

Flexible microneedles are important tools that allow access to the inside of biological tissue from the outside without surgery. However, it had been hard to realize microneedle sensor arrays on flexible substrates because of the difficulty of attaining a needle with a high Young's modulus for a selected area on a thin or soft substrate. In this work, we developed a microneedle sensor on a hybrid substrate based on high Young's modulus epoxy siloxane for the microneedles and low Young's modulus polydimethylsiloxane for the conformable substrate. Polyaniline was deposited on the microneedle for pH sensing. The mechanical durability of the device was assessed by insertion into pig skin 1000 times. Last, the flexible microneedle pH sensors showed their utility for monitoring pH distribution in rats in a peripheral artery diseases model.

Low-Temperature and High-Quality Growth of Bi2O2Se Layered Semiconductors via Cracking Metal-Organic Chemical Vapor Deposition.

Ternary metal-oxy-chalcogenides are emerging as next-generation layered semiconductors beyond binary metal-chalcogenides (i.e., MoS2). Among ternary metal-oxy-chalcogenides, especially Bi2O2Se has been demonstrated in field-effect transistors and photodetectors, exhibiting ultrahigh performance with robust air stability. The growth method for Bi2O2Se that has been reported so far is a powder sublimation based chemical vapor deposition. The first step for pursuing the practical application of Bi2O2Se as a semiconductor material is developing a gas-phase growth process. Here, we report a cracking metal-organic chemical vapor deposition (c-MOCVD) for the gas-phase growth of Bi2O2Se. The resulting Bi2O2Se films at very low growth temperature (∼300 °C) show single-crystalline quality. By taking advantage of the gas-phase growth, the precise phase control was demonstrated by modulating the partial pressure of each precursor. In addition, c-MOCVD-grown Bi2O2Se exhibits outstanding electrical and optoelectronic performance at room temperature without passivation, including maximum electron mobility of 127 cm2/(V·s) and photoresponsivity of 45134 A/W.