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As customizable biomaterials, hydrogels have attracted great promise in several industries, including drug delivery, tissue engineering, biosensing and regenerative medicine. Three-dimensional networks of these hydrophilic polymers exhibit special properties, such as increased water content, soft and flexible texture and biocompatibility, making them excellent candidates to simulate the extracellular matrix and promote cell development and tissue regeneration. In this review paper, we provide a comprehensive overview of hydrogels, focusing on the design concepts, synthesis processes and characterization techniques. Different types of hydrogel materials, including natural polymers, synthetic polymers and hybrid hydrogels, along with their unique properties and applications are discussed. Improvements in hydrogel-based platforms for controlled drug delivery are being investigated. Recent advances in bioprinting processes using hydrogels to create complex tissue constructs with excellent spatial control are also explored. Hydrogel performance is examined across multiple variables, including mechanical properties, degradation behavior and biological interactions, with an emphasis on the importance of tailoring hydrogel qualities for specific applications. This review paper also provides insights into future directions in hydrogel research, including stimuli-sensitive hydrogels, self-healing hydrogels and bioactive hydrogels, which promise promising advances in the field. In general, the aim of this review paper is to provide the reader with a detailed understanding of hydrogels and all of their potential applications, making them a valuable tool for scientists and researchers working on biomaterials and tissue engineering.

The aim of the present study was to search for the differential gene expression and measure the serum level of a number of biochemical parameters in the cold Zheng (CZ) and non-cold Zheng (NCZ) in patients receiving hemodialysis. Hemodialysis (HD) patients were randomly selected from the CZ and NCZ groups. The between-group differences in gene expression were assessed using complementary DNA (cDNA) microarray. Differential gene expression was further validated by real-time reverse transcriptase polymerase chain reaction (RT-PCR). Our results demonstrated that the up-regulation of the inflammation-associated genes, ALOX5AP, S100A8 and S100A12, down-regulation of the genes related to immunity (DEFA4), metabolism (GNG11, PYGB, PRKAR2B), and growth/proliferation (HSF2, DDR2, TK1) were found in the CZ group. Furthermore, the CZ HD patients had significantly lower serum albumin levels compared with their NCZ counterparts (3.31 ± 0.08 g/dL versus 4.18 ± 0.12 g/dL). It appears reasonable to conclude that up-regulated inflammatory-gene expression (ALOX5AP, S100A8 and S100A12) may play an important role in CZ HD patients.

Gallium(III) corroles are closed-shell analogs of zinc(II) porphyrins. These intensely fluorescent molecules can be modified readily to tune their solubility and photophysical properties. A water-soluble gallium corrole has been synthesized and investigated in depth; it binds tightly to human serum albumin, opening the possibility of using corroles as therapeutic agents as well as probes of biological structures.

The photophysical properties of tetrakis(1,1-dimethyl-2-trimethylammonium)ethylphthalocyaninato zinc(II) tetraiodide (I) – a water-soluble cationic phthalocyanine – are presented in the presence of human serum albumin (HSA) and in micelles of sodium dodecylsulfate (SDS) and hexadecyltrimethylammonium chloride (CTAC). Spectrophotometric measurements showed that the surfactants SDS and CTAC induce monomerization of I, although the latter less efficiently than the former. This effect is less pronounced in the presence of HSA. The strength of this effect is evaluated through dimerization constants, which are K_d = (5 ± 1) × 10⁵ m⁻¹ in SDS, (1.5 ± 0.5) × 10⁶M⁻¹ in CTAC, and (1.8 ± 0.9) × 10⁶M⁻¹ in HSA. Fluorescence experiments confirm that aggregation of I drops as the concentration of surfactant is raised. Triplet quantum yields also decreased upon aggregation and were Φ_T = 0.59, 0.16, and < 0.01 in SDS, CTAC, and HSA, respectively. These results indicate that the affinity of I for the environment is not just due to ionic interactions; hydrophobic interactions play an equally important role.

The thiosine dye methylene blue (MB) interaction with human serum albumin (HSA) has been studied. MB was revealed to stabilize the native structure of HSA, since the denaturation temperature of the complexes is shifted to higher values in relation to that of the pure protein. It was also revealed that the absorption spectra of the complexes do not change noticeably, while in the fluorescence spectra the maximal intensity of MB decreases with the albumin concentration enhancement. Analysis of the obtained data allows to conclude that the main binding mode of MB to HSA, providing the stabilization of the protein native structure, is the electrostatic mechanism.

Albumin is the most versatile carrier protein in plasma, possessing multiple functions; a reduced amount of albumin in the body is associated with different kinds of diseases such as hypovolemia and hypoproteinemia. The demand for albumin increased for various indications in shocks, burns, cardiopulmonary bypass, acute liver failure and research applications. Several potential problems associated with the preparation and administration of this substance arise from purity, sterilization process and vascular membrane permeability. The present review discusses the potential of metallic, quantum dots and carbon-based nanocarriers to improve the quality of blood products and the effect of these nanoparticles on albumin products. The effects of these nanoparticles on albumin products with a focus on toxicity aspects, structural alteration, stressing conditions, stabilizing agents and unwanted leakage are highlighted. Our literature review indicated the enhanced efficiency of AuNPs in metallic nanoparticles and better performance of negatively charged QDs on albumin products, which provided important information for possible safe use in medical applications. Moreover, among carbon-based nanoparticles, GO had relatively improved effects on albumin unwanted leakage and fibrillation. This review suggests an agenda for scientists to use and design nanoparticles to improve albumin products for various applications.

Injectable oxygen delivery is an emerging technology that presents an opportunity for improved patient care in a number of medical disciplines. Here, we report on the fabrication and characterization of novel protein-encapsulated oxygen microbubbles (OMBs) designed for intravenous injection. The nanothick albumin encapsulation provided OMBs small enough for transcapillary passage: 99% of the microbubbles were less than 3-μm diameter and less than 1% of the oxygen was encapsulated in microbubbles greater than 8-μm diameter. The protein OMBs were remarkably stable, losing less than 40% of the encapsulated gas over 12 days. Upon injection into an oxygen-depleted saline solution, the protein OMBs rapidly equilibrated by releasing their oxygen core. These results indicate that protein microbubbles may serve as a suitable platform for direct injection of bioactive and therapeutic gases.

Isolated pleural effusion is a rare presentation of severe OHSS. Two to four percent of women of reproductive age have subclinical hypothyroidism which is an uncommon association of late onset iatrogenic OHSS. This report describes an unusual patient with isolated unilateral pleural effusion and subclinical hypothyroidism as the only manifestation of late onset OHSS in a singleton pregnancy following in vitro fertilization (IVF). We have summarized current literature related to isolated pleural effusion in late OHSS and evaluated its pathophysiology and treatment options. Albumin infusion may be considered as a plasma expander whenever there is a planned third space drainage. Thyroid profile test in asymptomatic patients planning IVF will help to identify subclinical hypothyroidism. OHSS is a self-limiting condition and a timely diagnosis with aggressive management can be lifesaving.

Synovial fluid mediated boundary lubrication is the key mechanism dominating the wear process of the artificial joint materials. The most abundant composition in the synovial fluid is albumin. It has been observed that the increasing human serum albumin (HSA) concentration leads to the increasing friction coefficient under the articulation of ultra-high molecular polyethylene (UHMWPE) and CoCrMo alloy materials. In this study, the friction and adsorption experiments were carried out to investigate the effects from addition of hyaluronic acid (HA) molecules. Our results indicated that the increase in HA concentration level results in the decrease of the frictions under HSA-HA mixed lubrication conditions. Insertion of HA molecules at the interface provide a higher elasticity of the lubricating layer. This "damping" mode results in the slightly reduction of friction. More HA molecules may entrap the HSA molecules and then expel them away from the articulating surfaces. This "expelling" mode leads to a significant decrease of friction. The lubricating mechanism of hyaluronic acid on the albumin-mediated tribological processes between UHMWPE and CoCrMo materials was investigated and proposed in this study.

Perfluorocarbons are a class of substances ideally suited for the transport of respiratory gases in order to support tissue oxygenation when red blood cells are diminished or not available. As these totally synthetic molecules intrinsically avoid any infection risks and even stay functional in the presence of flue gases, they display (theoretical) advantages to hemoglobin-based artificial oxygen carriers. Unfortunately perfluorocarbons were abandoned by most of the researchers in favor of hemoglobin-based products as unresolved, harmful side effects, the halt of advanced clinical trials and financial reasons have been reported. At least some countries have recognized the potential of perfluorocarbons and clinically approved perfluorocarbon-based products.

However, we believe in these exceptional substances and thus want to increase the access to perfluorocarbon-based products by developing albumin-derived perfluorocarbon-based artificial oxygen carriers. This formulation is based on an idea dating back to the 1970s, which we have now transformed successfully. The aim of this study was to prove whether albumin-derived perfluorocarbon-based artificial oxygen carriers (capsules) can supply an isolated perfused rat heart (Langendorff model) with oxygen even under massive ischemic conditions induced by a reduction of the flow rate to only 20%. Capsules did not change the rheological properties of the Krebs–Henseleit buffer (KH-buffer) and could repeatedly reload with oxygen. Hearts perfused with capsules showed increased left ventricular pressure (LVDP) and rate pressure product (RPP, markers of heart vitality) compared to hearts perfused with a pure KH-buffer. The capsules prevented the myocardium from malfunctioning when in their absence a noxious ischemia was observed. Thus an albumin-derived perfluorocarbon-based artificial oxygen carrier preserved the function of the rats’ hearts due to the transport of oxygen in a satisfactory manner.