Cross-linking Technique Research Articles

Engineering alginate/carboxymethylcellulose scaffolds to establish liver cancer spheroids: Evaluation of molecular variances between 2D and 3D models

Natural polymeric hydrogels represent an optimal framework for 3D culture development. This study demonstrates a freeze-thaw-based ionic crosslinking technique for fabricating alginate/carboxymethylcellulose scaffold for culturing human hepatocellular carcinoma, Huh-7 cells to generate 3D spheroids. Consolidating morphological and biomechanical characterization of Alg/CMC scaffolds shows the formation of uniform hydrogels with significant crosslinking (ATR-FTIR), multiscale pores (FE-SEM), swelling/water absorbance, softer texture, viscoelasticity (rheology), spreading nature (contact angle), and degradation rate optimal for 3D culture establishment. The influence of cell seeding density and time with spheroid formation reveals a maximal size of 250–300 μm on day 7. Calcein AM and Propidium iodide staining confirm that a culmination of viable and dead cells generates spheroidal heterogeneity. RT-qPCR in 3D culture against RPL-13 and 2D culture controls indicate an upregulation of E-cadherin, N-cadherin, fibronectin, and integrin α9/β6. Further, western blotting and immunofluorescence confirm the collective display of cellular interactions in 3D spheroids. Thus, the expression profile signifies the role of key genes during the assembly and formation of 3D spheroids in 1%Alg/1%CMC scaffolds with a profound epithelial characteristic. In the future, this study will bring a 3D spheroid model in a platter for elucidating epithelial to mesenchymal transition of cells during in vitro disease modeling.

Biopolymers for Tissue Engineering: Crosslinking, Printing Techniques, and Applications.

Currently, tissue engineering has been dedicated to the development of 3D structures through bioprinting techniques that aim to obtain personalized, dynamic, and complex hydrogel 3D structures. Among the different materials used for the fabrication of such structures, proteins and polysaccharides are the main biological compounds (biopolymers) selected for the bioink formulation. These biomaterials obtained from natural sources are commonly compatible with tissues and cells (biocompatibility), friendly with biological digestion processes (biodegradability), and provide specific macromolecular structural and mechanical properties (biomimicry). However, the rheological behaviors of these natural-based bioinks constitute the main challenge of the cell-laden printing process (bioprinting). For this reason, bioprinting usually requires chemical modifications and/or inter-macromolecular crosslinking. In this sense, a comprehensive analysis describing these biopolymers (natural proteins and polysaccharides)-based bioinks, their modifications, and their stimuli-responsive nature is performed. This manuscript is organized into three sections: (1) tissue engineering application, (2) crosslinking, and (3) bioprinting techniques, analyzing the current challenges and strengths of biopolymers in bioprinting. In conclusion, all hydrogels try to resemble extracellular matrix properties for bioprinted structures while maintaining good printability and stability during the printing process.

A predictive model of UV-A-riboflavin crosslinking treatment on porcine corneas

The crosslinking technique (CXL) is an effective low-risk therapeutic treatment of keratoconus and other ectatic disorders of the human cornea. The effect of corneal CXL is to increase the stiffness of the stroma to prevent the progression of the cornea distortion. Several clinical and experimental studies have shown that the stiffening effects predominantly localize on the anterior portion of the stroma and that the in-depth stiffening distribution is highly dependent on the duration of treatment. Yet, how the stiffening effects distribute through the cornea thickness as a function of the treatment duration is an open question. Here, we propose an analytical model of the stiffening profile due to CXL treatment as a function of the irradiation time. We consider linear and nonlinear variations of the crosslinking effects across the thickness and implement them into a finite element model of the porcine cornea. We present a time-dependent in-depth stiffening profile that allows us to predict the post-operative cornea response to physiological intraocular pressure for different irradiation times. We anticipate that this predictive model will support the development of patient specific three-dimensional models that will allow clinicians to design customized CXL treatment, thus enhancing treatment outcomes.

Impact on quality of life of keratoconus patients treated with accelerated "epi-on" corneal collagen crosslinking technique: results from the NEI VFQ-25 Questionnaire in a Romanian population.

Objective: The main objective of this study was to describe vision-related quality of life (VRQoL) in a Romanian population of patients with keratoconus who underwent the accelerated "epi-on" corneal collagen crosslinking procedure and to evaluate the association with demographic data of age, gender and civil status (married, cohabitants or non-cohabitants). Method: The National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) was administered to 72 patients with keratoconus who had undergone a minimally invasive procedure. Descriptive statistics and bivariate analysis were used to determine the distribution of demographic parameters and a possible association between this parameter and the scores obtained on the NEI VFQ-25 questionnaire. Results: Based on the answers to the questionnaire we calculated the mean (SD) VFQ-25 total score, which was 73,97 (15,11), whilst scores for the subscales varied from 49.93 to 84,23. No significant difference was observed between the demographic parameters and the NEI VFQ-25 items, except for one item (being with others) when comparing paired and non-paired participants. Conclusion: In a Romanian population with keratoconus being treated with accelerated "epi-on" corneal collagen crosslinking procedure, VRQoL was reported at a high baseline level. The value of this information is significant when discussing patients' expectations during treatment. The VRQoL was not affected by age or civil status.

One pot synthesis of hydrophobic nanochitin aerogel via tert-butyl alcohol/water binary solvents as antibacterial and renewable oil superabsorbent

In this study, hydrophobic nanochitin aerogels are synthesized via one-pot synthesis strategy and subsequent freeze-drying technique, employing nanochitin, hexanal and formaldehyde as primary components. The tert-butyl alcohol (TBA)/water binary solvents are found efficient for well mixing of hydrophilic nanochitin and hydrophobic hexanal, which is fundamental for fabricating hydrophobic aerogels with water contact angle as high as 105°. Schiff base reaction between amino groups in nanochitin and aldehyde groups in hexanal is believed to be the main reason for the successful hydrophobization of nanochitin aerogels. Additionally, formaldehyde is employed to enhance the mechanical properties of aerogels via ice templated crosslinking technique. Nanochitin aerogels prepared in this work possess surface area as high as 237 m2 g−1, which are believed benefiting from the TBA/water binary solvents with lower density, smaller ice crystal and convenience in freeze-drying. The ultralow density, ultrahigh porosity, and hydrophobicity nature also lead to the advanced oil adsorption (as high as 210 g g−1) of nanochitin aerogels. The simple preparation process, nature sustainability and excellent adsorption performance is believed rendering nanochitin aerogels as a viable alternative for the remediation of oil spills.

Reduced graphene oxide-TiO2/sodium alginate/polyacrylamide composite hydrogel for enhanced adsorption-photocatalytic degradation of methylene blue

The discharge of dye wastewater from various industries has emerged as a critical environmental concern, necessitating the implementation of effective methods such as photocatalytic technology to mitigate organic dyes in water. Nevertheless, the poor photocatalytic activityability and low reusability of most semiconductor photocatalysts have hindered their large-scale practical application. In this paper, the reduced graphene oxide-titanium dioxide composite (rGO-TiO2) was prepared via a hydrothermal method and subsequently immobilized onto a three-dimensional structure composed of sodium alginate (SA) and polyacrylamide (PAM) through sunlight-induced polymerization and ionic cross-linking techniques, resulting in the fabrication of a novel photocatalytic composite hydrogel (rGO-TiO2/SA/PAM). The composite hydrogel was found to exhibit good photocatalytic degradation efficiency for methylene blue(MB), achieving complete removal of MB under UV light irradiation for 100 min at pH 7 when using a rGO:TiO2 ratio of 3 wt%. Additionally, the synthesis of rGO-TiO2/SA/PAM effectively harnesses solar resources through simple synthetic steps, enabling easy recovery and separation from dye wastewater (with a recovery rate of approximately after first use). In contrast, nano-TiO2 and rGO-TiO2 exhibit lower recovery rates (∼80%). Furthermore the material demonstrates enhanced selective adsorption-photocatalytic degradation of MB in acid-base dye mixtures under UV light irradiation.

ESI-IM-MS characterization of cyclodextrin complexes and their chemically cross-linked alpha (α-), beta (β-) and gamma (γ-) cyclodextrin particles as promising drug delivery materials with improved bioavailability.

Cyclodextrins (CDs) are natural cyclic oligosaccharides with a relatively hydrophobic cavity and a hydrophilic outer surface. In this study, alpha (α-), beta (β-) and gamma (γ-) CD particles were prepared by directly using α-, β-, and γ-CDs as monomeric units and divinyl sulfone (DVS) as a crosslinker in a single-step via reverse micelle microemulsion crosslinking technique. Particles of p(α-CD), p(β-CD), and p(γ-CD) were perfectly spherical in sub- 10µm size ranges. The prepared p(CD) particles at 1.0mg/mL concentrations were found biocompatible with >95 % cell viability against L929 fibroblasts. Furthermore, p(α-CD) and p(β-CD) particles were found non-hemolytic with <2 % hemolysis ratios, whereas p(γ-CD) particles were found to be slightly hemolytic with its 2.1±0.4 % hemolysis ratio at 1.0mg/mL concentration. Furthermore, a toxic compound, Bisphenol A (BPA) and a highly antioxidant polyphenol, curcumin (CUR) complexation with α-, β-, and γ-CD molecules was investigated via Electrospray-Ion Mobility-Mass Spectrometry (ESI-IM-MS) and tandem mass spectrometry (MS/MS) analysis. It was determined that the most stable noncovalent complex was in the case of β-CD, but the complex stoichiometry was changed by the hydrophobic nature of the guest molecules. In addition, BPA and CUR were separately loaded into prepared p(CD) particles as active agents. The drug loading and release studies showed that p(CD) particles possess governable loading and releasing profiles.

Comparison of the Eggshell and the Porcine Pericardium Membranes for Guided Tissue Regeneration Applications.

Guided bone regeneration is frequently used to reconstruct the alveolar bone to rehabilitate the mastication using dental implants. The purpose of this article is to research the properties of eggshell membrane (ESM) and its potential application in tissue engineering. The study focuses on the structural, mechanical, and histological characteristics of ESM extracted from Gallus domesticus eggs and to compare them to a commercially available porcine pericardium membrane (Jason® membrane, botiss biomaterials GmbH, Zossen, Germany). Thus, histology was performed on the ESM, and a comparison of the microstructure through scanning electron microscopy and atomic force microscopy (AFM) was conducted. Also, mechanical tensile strength was evaluated. Samples of ESM were prepared and treated with alcohol for fixation and disinfection. Histological analysis revealed that the ESM architecture is constituted out of loose collagen fibers. However, due to the random arrangement of collagen fibers within the membrane, it might not be an effective barrier and occlusive barrier. Comparative analyses were performed between the ESM and the AFM examinations and demonstrated differences in the surface topography and mechanical properties between the two membranes. The ESM exhibited rougher surfaces and weaker mechanical cohesion attributed to its glycoprotein content. The study concludes that while the ESM displays favorable biocompatibility and resorb ability, its non-uniform collagen arrangement limits its suitability as a guided bone regeneration membrane in the current non-crosslinked native form. Crosslinking techniques may enhance its properties for such applications. Further research is needed to explore modifications and processing methods that could leverage the ESM's unique properties for tissue engineering purposes.

Effect and mechanism of a concentration-dependent inorganic ion biomimetic periosteum in a repairing bone defect

An inorganic ion functionalized biomimetic periosteum constitutes a new strategy for the design and application of new bone repair materials. However, the effect of cumulative concentration of inorganic ions (e.g. inorganic ion (Si4+)) on bone immune microenvironment in promoting bone repair is still unclear. Here, we used different mesoporous bioactive glass nanoparticles (MBGNs) contents and a methacrylic acid gelatin (GelMA) organic–inorganic double crosslinking techniques to construct low, medium, and high content inorganic ion biomimetic periosteum. As the inorganic ion concentration increased, the compression modulus of LM@G, MM@G, and HM@G (1, 3, and 5 wt% MBGNs, respectively) was 1.6, 3.2, and 2.1 times higher than that of the GelMA hydrogel and the Si4+ release was 35.4 ± 0.4, 59.5 ± 0.2, and 71.5 ± 1.2 ppm in vitro, respectively. The ERK1/2 and p65 inhibition in the HM@G was 51.9% and 40.2% higher than that in the LM@G; however, the stem cell recruitment was about 85.2% lower than that in the LM@G, and the vascular germination degree was 35.4% lower than that in the MM@G. Contradiction between immune regulation and bone repair was found. However, the anti-inflammation in the MM@G was 30.8%, 30.1% higher than that in the LM@G, and stem cell recruitment and vascular sprouting were 3.4 and 1.6 times higher, respectively than those in the HM@G. In summary, the anti-inflammatory effect of MM@G group is stronger than that of LM@G group, and the effect of stem cell recruitment is more significant than that of HM@G group. We not only explore the biological mechanism of Si4+ coordinating macrophages and stem cells to promote bone repair, but also provide research basis for designing inorganic ion based immunofunctional biomaterials.

Development of environmentally friendly soft contact lenses made from cellulose-derived hydrogel materials

With the performance improvement of soft contact lenses (SCLs) over the past few decades, their global use and market have steadily expanded. Consequently, contamination by disposable SCLs has become a potential threat to the environment. From the perspective of sustainable development goals, overcoming this issue requires the development of new biodegradable SCL materials based on plant-derived cellulose. In this study, highly transparent hydrogels based on hydroxypropyl cellulose were prepared via a radiation crosslinking technique using electron beams. By optimizing the irradiation dose and type of added monomer, excellent physicochemical properties, such as mechanical strength and transparency, and biological properties, such as low lysozyme deposition and biodegradability, were obtained. Thus, hydrogels produced by radiation crosslinking can be potentially used as human- and environment-friendly SCL materials.

A mist-based crosslinking technique for coaxial bioprinting of hollow hydrogel fibers

In this paper, a mist-based method for coaxial three-dimensional bioprinting of ionically crosslinking hydrogel hollow fibers is presented. Unlike current techniques of coaxial bioprinting that utilize the crosslinker in liquid or sacrificial form, the developed method introduces the core crosslinking agent in mist form. The use of mist as a core flow provides adequate pressure and sufficient crosslinking to maintain the tubular shape of a hollow fiber. Through controlled exposure of crosslinker, the developed system prevents poor resolution and layer adhesion caused by the accumulation of liquid crosslinker on the printbed. Furthermore, it eliminates additional processing steps, such as partial crosslinking of the hydrogel prior- or removal of sacrificial material post-printing. The printability and mechanical properties of hollow fiber scaffolds printed using various mist and hydrogel concentrations are studied. It is shown that mist concentration influences the gelation rate of the hollow fiber, impacting the shape fidelity, layer adhesion, and mechanical properties of the printed structures. Moreover, the effects of printing parameters, including the mist core pressure and hydrogel flowrate, on the diameter and wall thickness of the hollow fiber are investigated. Finally, scaffolds printed and crosslinked using mist exhibit over 90% cell viability. The developed mist-based coaxial system enables direct printing of continuous hollow fibers.

Graft rejection in paediatric congenital heart disease.

Congenital heart disease (CHD) affects around 1.35 million neonates worldwide per annum, and surgical repair is necessary in approximately 25% of cases. Xenografts, usually of bovine or porcine origin, are often used for the surgical reconstruction. These xenografts elicit an immune response due to significant immunological incompatibilities between host and donor. Current techniques to dampen the initial hyperacute rejection response involve aldehyde fixation to crosslink xenoantigens, such as galactose-α1,3-galactose and N-glycolylneuraminic acid. While this temporarily masks the epitopes, aldehyde fixation is a suboptimal solution, degrading over time, resulting in cytotoxicity and rejection. The immune response to foreign tissue eventually leads to chronic inflammation and subsequent graft failure, necessitating reintervention to replace the defective bioprosthetic. Decellularisation to remove immunoincompatible material has been suggested as an alternative to fixation and may prove a superior solution. However, incomplete decellularisation poses a significant challenge, causing a substantial immune rejection response and subsequent graft rejection. This review discusses commercially available grafts used in surgical paediatric CHD intervention, looking specifically at bovine jugular vein conduits as a substitute to cryopreserved homografts, as well as decellularised alternatives to the aldehyde-fixed graft. Mechanisms of biological prosthesis rejection are explored, including the signalling cascades of the innate and adaptive immune response. Lastly, emerging strategies of intervention are examined, including the use of tissue from genetically modified pigs, enhanced crosslinking and decellularisation techniques, and augmentation of grafts through in vitro recellularisation or functionalisation with human surface proteins.

Facile fabrication of Artemisia sphaerocephala krasch gum hydrogels by radiation induced cross-linking polymerization and enhanced ultrahigh adsorption for methylene blue

Although Artemisia sphaerocephala krasch gum (ASKG) has attracted growing attention in the field of medical engineering and food industries, however, there are few studies on the gelation of ASKG. In this paper, acrylic acid modified ASKG hydrogels were prepared by radiation induced grafting, cross-linking and polymerization technique for the first time. The semi-IPN structure was prepared by the cross-linked ASKG network and poly-AAc dispersed within the network. The effects of the adsorbed dose on the swelling ratio and gel fraction were investigated. The different acrylic acid content modified ASKG hydrogels (ASKGAAc1 and ASKGAAc2) for methyl blue (MB) adsorption were investigated, and the ASKG hydrogels was also studied for comparison. The influence of pH, contact time, initial concentration, temperature, ion strength on MB adsorption were tested. The results showed that acrylic acid can promote the formation of hydrogel and greatly enhanced the adsorption of ASKG. The adsorption isotherms were well obeyed the Langmuir model, and the maximum adsorption capacity for MB of ASKG, ASKGAAc1 and ASKGAAc2 were 571.43, 1517.8 and 1654.9 mg/g, respectively. Moreover, the MB adsorption by ASKG based hydrogels was exothermic, spontaneous, and more favorable at lower temperature. Furthermore, the adsorption-desorption experiments demonstrated a good reusability of these hydrogels.

Tendon-derived matrix crosslinking techniques for electrospun multi-layered scaffolds.

Tendon tears are common and healing often occurs incompletely and by fibrosis. Tissue engineering seeks to improve repair, and one approach under investigation uses cell-seeded scaffolds containing biomimetic factors. Retention of biomimetic factors on the scaffolds is likely critical to maximize their benefit, while minimizing the risk of adverse effects, and without losing the beneficial effects of the biomimetic factors. The aim of the current study was to evaluate cross-linking methods to enhance the retention of tendon-derived matrix (TDM) on electrospun poly(ε-caprolactone) (PCL) scaffolds. We tested the effects of ultraviolet (UV) or carbodiimide (EDC:NHS:COOH) crosslinking methods to better retain TDM to the scaffolds and stimulate tendon-like matrix synthesis. Initially, we tested various crosslinking configurations of carbodiimide (2.5:1:1, 5:2:1, and 10:4:1 EDC:NHS:COOH ratios) and UV (30 s 1 J/cm2 , 60 s 1 J/cm2 , and 60 s 4 J/cm2 ) on PCL films compared to un-crosslinked TDM. We found that no crosslinking tested retained more TDM than coating alone (Kruskal-Wallis: p > .05), but that human adipose stem cells (hASCs) spread most on the 60 s 1 J/cm2 UV- and 2.5:1:1 EDC-crosslinked films (Kruskal-Wallis: p < .05). Next, we compared the effects of 60 s 1 J/cm2 UV- and 2.5:1:1 EDC-crosslinked to TDM-coated and untreated PCL scaffolds on hASC-induced tendon-like differentiation. UV-crosslinked scaffolds had greater modulus and stiffness than PCL or TDM scaffolds, and hASCs spread more on UV-crosslinked scaffolds (ANOVA: p < .05). Fourier transform infrared spectra revealed that UV- or EDC-crosslinking TDM did not affect the peaks at wavenumbers characteristic of tendon. Crosslinking TDM to electrospun scaffolds improves tendon-like matrix synthesis, providing a viable strategy for improving retention of TDM on electrospun PCL scaffolds.

Encapsulated Zataria multiflora's essential oil inhibited the growth of Aspergillus flavus and reduced aflatoxins levels in contaminated pistachio nut

The essential oil of Zataria multiflora Boiss. (ZEO) was prepared using a British Pharmacopeia-type hydrodistillation apparatus. The ZEO was encapsulated with a natural polymer, chitosan (CS) by oil-in-water emulsification, and ionic cross-linking techniques. The shape and size range of the encapsulated particles were evaluated by Atomic-Force Microscopy (AFM) and Dynamic Light Scattering (DLS) and FT-IR spectroscopy. The AFM analysis of the ZEO encapsulated nano-particles (CS-ZEO) showed spherical shape particles with inner cavities. The mean size of CS-ZEO particles was 293 ± 17 nm according to DLS analysis. The chemical constituent of the oil was analyzed by GC-MS and thymol acetate (32.4%), carvacrol acetate (19.0%), γ-terpinene (18.5%), and ρ-cymene (14.5%) were reported as its major constituents. The non-encapsulated ZEO in the synthesis process was determined to calculate the encapsulation efficiency and loading capacity of the prepared CS-ZEO which were 87.4% and 6%; respectively. In vitro antifungal activity of ZEO and CS-ZEO in growth media against Aspergillus flavus was evaluated with the decrease in fungal mycelial mass. On the other hand, the HPLC results showed the reduction of aflatoxins B1 levels by 95% and 92% at concentrations of 0.8 mg/mL of ZEO and 6.7 mg/mL of CS-ZEO, respectively. The above-mentioned effective concentrations of the ZEO and CS-ZEO, were applied to pistachio samples, which reduced 90.5% and 99.0%, of the aflatoxin B1 levels, respectively compared to non-treated samples. Therefore, we suggest here, the CS-ZEO as a possible natural fungicide with an effective mechanism of lowering aflatoxins production in the contaminated pistachio.

Acromion and Distal Clavicle Grafts for Arthroscopic Glenoid Reconstruction.

We intended to determine if an acromion or distal clavicle bone graft could restore large glenoid defects using two novel, screw-free graft fixation techniques. Twenty-four sawbone shoulder models were divided into four groups (n = 6 per group) according to fixation technique and bone graft: (1) modified buckle-down technique with clavicle graft, (2) modified buckle-down technique with acromion graft, (3) cross-link technique with acromion graft, (4) cross-link technique with clavicle graft. Testing was performed sequentially in (1) intact models, (2) after creation of a 30% by-width glenoid defect and (3) after repair. The shoulder joint was translated anteriorly, and glenohumeral contact pressures and load were measured to quantify the biomechanical stability. Maximum contact pressures were restored to 42-56% of intact glenoid using acromion and clavicle grafts with novel fixation techniques. Acromion grafts attained higher maximum contact pressures than clavicle grafts in all groups. Peak translational forces increased by 171-368% after all repairs. This controlled laboratory study on sawbone models found that both the acromion and distal clavicle are suitable autologous bone graft options for treating large anterior glenoid defects, having appropriate dimensions and contours for reconstructing the glenoid arc. The modified buckle-down and cross-link techniques are two graft fixation techniques that restore stability to the shoulder joint upon repairing a large glenoid defect and are advantageous in being screw-free and simple to execute.

Is refractive enhancement a safer option for post laser in situ keratomileusis and small incision lenticule extraction regression - How far we have come?

Is refractive enhancement a safer option for post laser in situ keratomileusis and small incision lenticule extraction regression - How far we have come?

Toxicity reduction of natural rubber gloves using protein crosslinking technique

AbstractFor natural rubber (NR) gloves, residual latex processing chemicals are the important substances that cause adverse reactions to users who are sensitive to them. Many attempts have therefore been made to reduce or eliminate these leachable chemicals from the gloves such as natural compound addition and polymer coating. The current study proposed a novel alternative method to reduce chemical allergens from NR gloves by protein crosslinking through the Maillard reaction that is possible to adapt to the existing glove production. Commercial NR gloves were initially treated with various concentrations of glutaraldehyde, a crosslinking agent, ranging from 0.00% to 1.00%w/w prior to being tested for cytotoxicity, contact angle, water absorption, and mechanical properties. Artificial sweat and culture medium with serum (complete medium) were used as vehicles for in vitro cytotoxicity tests. Results from the test revealed that, regardless of the vehicle type, increasing glutaraldehyde concentration reduced the toxicity of NR gloves, indicating the reduction of leachable toxic substances after the treatment. Contact angle and water absorption resistance were found to increase with increasing glutaraldehyde concentration, reflecting the enhanced hydrophobicity of the treatment. The mechanical properties of the gloves were not significantly different after such treatment. The results confirm the potential use of this protein crosslinking method to reduce the allergy problem of NR gloves.

Advantages and limitations of UV cross-linking analysis of protein-RNA interactomes in microbes.

RNA-binding proteins (RBPs) govern the lifespan of nearly all transcripts and play key roles in adaptive responses in microbes. A robust approach to examine protein-RNA interactions involves irradiating cells with UV light to form covalent adducts between RBPs and their cognate RNAs. Combined with RNA or protein purification, these procedures can provide global RBP censuses or transcriptomic maps for all target sequences of a single protein in living cells. The recent development of novel methods has quickly populated the RBP landscape in microorganisms. Here, we provide an overview of prominent UV cross-linking techniques which have been applied to investigate RNA interactomes in microbes. By assessing their advantages and caveats, this technical evaluation intends to guide the selection of appropriate methods and experimental design as well as to encourage the use of complementary UV-dependent techniques to inspect RNA-binding activity.

Regulating Type H Vessel Formation and Bone Metabolism via Bone‐Targeting Oral Micro/Nano‐Hydrogel Microspheres to Prevent Bone Loss (Adv. Sci. 15/2023)

Osteoporosis A pH-responsive shell-core structured micro/nano-hydrogel microspheres construct via gas microfluidics and ionic cross-linking technique. The microspheres can achieve oral delivery, intragastric protection, intestinal slow/controlled release, and active targeting to bone tissue. This novel oral microspheres can simultaneously accelerate intraosseous vascularization and decrease bone resorption, offering a brand-new approach to prevent postmenopausal osteoporosis. More details can be found in article number 2207381 by Wenguo Cui, Peng Jia, Youjia Xu, and co-workers.