Porous hydrogel arrays for hepatoma cell spheroid formation and drug resistance investigation

Drug resistance is one of the major obstacles in the drug therapy of cancers.Efforts in this area in pre-clinical research have focused on developing novel platforms to evaluate and decrease drug resistance.In this paper,inspired by the structure of hives where swarms live and breed,we propose porous hydrogel arrays with a uniform pore structure for the generation of hepatoma cell spheroids and the investigation of drug resistance.The porous hydrogel arrays were fabricated using polyeth-ylene glycol diacrylate(PEGDA)hydrogel to negatively replicate a well-designed template.Benefiting from the elaborate processing of the template,the prepared porous hydrogel arrays possessed a uniform pore structure.Due to their anti-adhesion properties and the excellent biocompatibility of the PEGDA hydrogel,the hepatoma cells could form well-defined and uni-form hepatoma cell spheroids in the porous hydrogel arrays.We found that the resistant hepatoma cell spheroids showed more significant Lenvatinib resistance and a migratory phenotype compared with a two-dimensional(2D)cell culture,which reveals the reason for the failure of most 2D cell-selected drugs for in vivo applications.These features give such porous hydrogel arrays promising application prospects in the investigation of tumor cell spheroid culture and in vitro drug resistance.

Linearly shifting ferromagnetic resonance response of La_(0.7)Sr_(0.3)MnO_(3) thin film for body temperature sensors

Human body temperature not only reflects vital signs,but also affects the state of various organs through blood circulation,and even affects lifespan.Here a wireless body temperature detection scheme was presented that the temperature was extracted by investigating the out-of-plane(OP)ferromagnetic resonance(FMR)field of 10.2 nm thick La_(0.7)Sr_(0.3)MnO_(3)(LSMO)film using electron paramagnetic resonance(EPR)technique.Within the range of 34-42℃,the OP FMR field changes linearly with the increasing or decreasing temperature,and this variation comes from the linear responses of magnetization to the fluctuant temperature.Using this method,a tiny temperature change(<0.1℃)of organisms can be detected accurately and sensitively,which shows great potential in body temperature monitoring for humans and mammals.

Supramolecular G-quadruplex hydrogels:Bridging fabrication to biomedical application

G-quadruplex hydrogel is a class of self-assembled supramolecular hydrogel formed by guanine derivatives.As a biomimetic hydrogel,G-quadruplex hydrogels demonstrate wide biomedical applications,such as drug delivery,tissue engineering,and biosensing.The advantages of using G-quadruplex hydrogels include adequate biocompatibility and biodegradability,tunable multifunctionality,and cost-effective and large-scalable fabrication process.In this review,we focus on recent progress in the fabrication and characterization of G-quadruplex hydrogels to help readers understand the principles of G-quadruplex hydrogel formation.Meanwhile,the applications of G-quadruplex hydrogels in the biomedical area are discussed,aiming to pave the way for downward clinical or industry translation.The development of G-quadruplex hydrogel is still in its infancy.We hope this review will boost the development of this area and that more applications of G-quadruplex hydrogel will be developed.

Dynamic covalent nano-networks comprising antibiotics and polyphenols orchestrate bacterial drug resistance reversal and inflammation alleviation

New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms.This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks(aDCNs)composing antibiotics bearing multiple primary amines,polyphenols,and a cross-linker acylphenylboronic acid.Mechanistically,the iminoboronate bond drives the formation of aDCNs,facilitates their stability,and renders them highly responsive to stimuli,such as low pH and high H2O2 levels.Besides,the representative A1B1C1 networks,composed of polymyxin B1(A1),2-formylphenylboronic acid(B1),and quercetin(C1),inhibit biofilm formation of drug-resistant Escherichia coli,eliminate the mature biofilms,alleviate macrophage inflammation,and minimize the side effects of free polymyxins.Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model.The facile synthesis,excellent antimicrobial performance,and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.

Pollens derived magnetic porous particles for adsorption of low-density lipoprotein from plasma

Adsorption of low-density lipoprotein from plasma is vital for the treatment of dyslipidemia.Appropriate adsorbent material for efficient and selective adsorption of low-density lipoprotein is highly desired.In this work,we developed pollens-derived magnetic porous particles as adsorbents for this purpose.The natural pollen grains were modified to obtain high surface porosity,a large inner cavity,magnet responsiveness,and specific wettability.The resultant particles exhibited satisfying performance in the adsorption of a series of oils and organic solvents out of water.Besides,the particles were directly utilized to the adsorption of low-density lipoprotein in plasma,which showed high selectivity,and achieved an outstanding adsorption capacity as high as 34.9%within 2 h.Moreover,their salient biocompatibility was demonstrated through simulative hemoperfusion experiments.These features,together with its abundant source and facile fabrication,makes the pollens-derived magnetic porous particles excellent candidate for low-density lipoprotein-apheresis and water treatment applications.

交换偏置多铁异质结中电场调控可逆性磁化反转的矢量分析研究

铁磁与反铁磁层间的交换偏置效应已在自旋电子器件中得到了广泛应用.目前,利用电场调控这一低能耗的方式已经实现了对交换偏置磁性多层膜中如交换偏置场和磁化值等宏观性质的调节.然而,交换偏置体系中磁畴如何随施加电场进行演化却鲜有报道.本文采用定量磁光克尔效应(MOKE)显微成像系统,实现了原位矢量分析CoFeB/IrMn/PMN-PT(011)交换偏置多铁异质结中电场作用下的可逆磁化反转.在保持偏置磁场于-80 Oe不变的情况下,外加电场驱动磁畴的磁化方向在160°方向与80°-120°方向区间内往复变化,对应磁畴的横向分量也于225°方向与45°方向间来回切换.同时,通过逐像素比对不同电场下的磁畴,进一步证实了电场调节磁化反转的可逆性.此外,在零偏置磁场下也实现了对磁化反转的可逆电场调节.电场调控交换偏置的矢量分析对于理解磁电效应以及发展下一代自旋电子器件具有重要意义.

Ellipsoidal porous patch with anisotropic cell inducing ability for inhibiting skin scar formation

Scar formation has always been a difficult point to overcome in the field of clinical wound care.Here,we present an ellipsoidal porous patch with cell inducing ability for inhibiting scar formation.The patch was prepared by stretching a poly(lactic-co-glycolic acid)(PLGA)inverse opal film at the glass transition temperature to form a neatly arranged three-dimensional ellipsoidal porous structure.Such anisotropic structure showed dramatic capability in directing cell growth and arrangement by reconstructing cell morphology.Besides,the prolifera-tion of cells growing on the stretched patch was significantly suppressed without cell cytotoxicity.In addition,benefitting from the abundant and connected nanopores,the patch could be imparted with a potent ability to promote cell migration by encapsulating fibroblast growth factor 2(FGF2)via the second filling of functional gelatin methacryloyl(GelMA)hydrogel into its scaffold.In a typical scar model,we have demonstrated that the resultant patch performed well in inhibiting scar formation characterized by inhibiting the excessive proliferation of fibroblasts,decreasing the deposition of type I collagen,reducing the scar index and achieved complete tissue reconstruction.These results indicate the anisotropic inverse opal patch has an excellent application prospect in inhibiting scar formation during wound repair.