Wildan Mubarok

This study investigates the feasibility of using cincau perdu (Premna oblongifolia) as a single-ingredient hydrogel ink for extrusion-based 3D food printing targeted for dysphagia-friendly applications. Cincau perdu (CP), also known as grass jelly, is a traditional jelly-like dessert popular in Southeast Asia. CP hydrogels could be rapidly prepared by microwave-assisted heating, followed by cooling to room temperature. The rheological properties, stiffness, and syneresis of the hydrogels could be adjusted by changing the hydrogels’ concentration. 3D constructs faithful to the blueprint could be fabricated using inks composed of 10 w/v% CP hydrogels. The textural properties were tunable by altering the geometry (grid type and height) of the printed construct. The CP hydrogels were categorized as level 5 (minced and moist) criteria based on the International Dysphagia Diet Standardization Initiative (IDDSI), making them suitable for diets of patients with dysphagia. Taken together, these findings demonstrate the potential of CP hydrogels as a sustainable, naturally gelling, and culturally relevant material for 3D-printed diets for patients with dysphagia.

Enzymatically crosslinked hydrogels are important in biomedical applications. However, conventional horseradish peroxidase (HRP)-based systems are expensive, unstable, and potentially immunogenic. Herein, we introduce hemin/albumin complexes as cost-effective and biocompatible catalysts for phenol-mediated hydrogel formation. Phenolated bovine serum albumins (BSA-LPh, -MPh, and-HPh) with different degrees of substitution were synthesized and complexed with hemin. Spectroscopic analysis demonstrated that phenol modification altered the hemin microenvironment, resulting in distinct shifts in the Soret band. Functional assays revealed that albumin complexation enhanced catalytic activity compared to hemin alone. Moderate phenol modification provided an optimal balance between catalytic efficiency and hydrogel integration, whereas excessive modification reduced the performance of the enzyme. Hydrogels containing hemin/BSA-Ph complexes exhibited controllable protein retention and high cytocompatibility (>90%) with mouse fibroblast 10T1/2 cells. These findings demonstrate that hemin/albumin complexes are promising, cost-effective, and cytocompatible alternatives to HRP systems for hydrogel-based biomedical and nonclinical applications.

The development of hydrogels that allow vascular endothelial cells to form capillary-like networks is critical for advancing tissue engineering and drug discovery. In this study, we developed hydrogels composed of phenolated hyaluronic acid (HA-Ph) with an average molecular weight of 490–159 kDa via sonication in an aqueous solution. These hydrogels were synthesized by the horseradish peroxidase-catalyzed crosslinking of phenol moieties in the presence of hydrogen peroxide and phenolated gelatin. The sonication-degraded HA-Ph (198 kDa) significantly enhanced the migration ability of human umbilical vein endothelial cells (HUVECs) on cell culture plates when added to the medium compared to the original HA-Ph (490 kDa) and less-degraded HA-Ph (312–399 kDa). In addition, HUVECs cultured on these hydrogels formed networks that did not occur on hydrogels made from the original HA-Ph. CD44 expression and PI3K gene expression, both markers related to angiogenesis, were 3.5- and 1.8-fold higher, respectively, in cells cultured on sonication-degraded HA-Ph hydrogels than in those cultured on hydrogels comprising the original HA-Ph. These results highlight the potential of hydrogels containing sonication-degraded HA-Ph for tissue engineering and drug-screening applications involving human vascular endothelial cells.

In vitro network formation by endothelial cells serves as a fundamental model for studies aimed at understanding angiogenesis. The morphogenesis of these cells to form a network is intricately regulated by the mechanical and biochemical properties of the extracellular matrix. Here the effects of modulating these properties in hydrogels derived from phenolated hyaluronic acid (HA‐Ph) and phenolated gelatin (Gelatin‐Ph) are presented. Visible‐light irradiation in the presence of tris(2,2′‐bipyridyl)ruthenium(II) chloride hexahydrate and sodium persulfate induces the crosslinking of these polymers, thereby forming a hydrogel and degrading HA‐Ph. Human vascular endothelial cells form networks on the hydrogel prepared by visible‐light irradiation for 45 min (42 W cm⁻² at 450 nm) but not on the hydrogels prepared by irradiation for 15, 30, or 60 min. The irradiation time‐dependent degradation of HA‐Ph and the changes in the mechanical stiffness of the hydrogels, coupled with the expressions of RhoA and β‐actin genes and CD44 receptors in the cells, reveal that the network formation is synergistically influenced by the hydrogel stiffness and HA‐Ph degradation. These findings highlight the potential of tailoring HA‐based hydrogel properties to modulate human vascular endothelial cell responses, which is critical for advancing their application in vascular tissue engineering.

Bone morphogenetic protein 2 (BMP-2) is a protein or growth factor that plays an important role in osteogenic differentiation. Recently, there is an increasing demand for BMP-2, as it is the only osteoinductive growth factor approved by the Food and Drug Administration (FDA) as a substitute for bone grafts. However, recombinant BMP-2 production suffers from low production yields and changes in the biological function of the protein due to the low efficiency of translocation in production hosts. One of the key regulators that influences the efficiency of protein translocation is the signal peptide (SP). SP regulates the process of post-translational protein modification, which determines the fate of the synthesized protein. This literature review aims to explore the role of SP in the process of recombinant protein production in mammalian cells and the utilization of SP in BMP-2 production in the secretome of mesenchymal stem cells (MSCs). The production of recombinant proteins in the MSC secretome is expected to be an innovative therapy because it combines the positive effects of the secretome and BMP-2 together for bone healing.

Recently, there has been a growing interest in artificial skin on hydrogels as a potential alternative for animal testing to evaluate the efficacy and safety of Recently, there has been a growing interest in artificial skin on hydrogels as a potential alternative for animal testing to evaluate the efficacy and safety of

Hyaluronic acid/gelatin composite hydrogels with properties tuned by controlling the exposure time to H ₂ O ₂ show great promise as platforms for muscle cell sheet fabrication.

The study of the capillary-like network formation of human umbilical vein endothelial cells (HUVECs) in vitro is important for understanding the factors that promote or inhibit angiogenesis. Here, we report the behavior of HUVECs on the composite hydrogels containing hyaluronic acid (HA) and gelatin with different degrees of degradation, inducing the different physicochemical properties of the hydrogels. The hydrogels were obtained through horseradish peroxidase (HRP)-catalyzed hydrogelation consuming hydrogen peroxide (H₂O₂, 16 ppm) supplied from the air, and the degradation degree was tuned by altering the exposure time to the air. The HUVECs on the composite hydrogel with intermediate stiffness (1.2 kPa) obtained through 120 min of the exposure were more elongated than those on the soft (0.4 kPa) and the stiff (2.4 kPa) composite hydrogels obtained through 15 min and 60 min of the exposure, respectively. In addition, HUVECs formed a capillary-like network only on the stiff composite hydrogel although those on the hydrogels with comparable stiffness but containing gelatin alone or alginate instead of HA did not form the network. These results show that the HA/gelatin composite hydrogels obtained through the H₂O₂-mediated crosslinking and degradation could be a tool for studies using HUVECs to understand the promotion and inhibition of angiogenesis.