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Hydrogel is a versatile material that can be manipulated to achieve the desired physicochemical properties, such as stiffness, pore size, and viscoelasticity. Traditionally, these properties have been controlled through parameters such as concentration and pH adjustments. In this study, we focused on exploring the potential of hydrolyzed silk fibroin (HSF) as a molecular weight-modulating agent to control the physicochemical properties of double-composite hydrogels. We developed a synergistic dual-crosslinked hydrogel by combining ionically crosslinked silk fibroin with gellan gum (GG). The hydrolysis of silk fibroin not only enhanced its hydrophilicity but also enabled adjustments in its mechanical properties, including the pore size, initial modulus elasticity, and relaxation time. Moreover, biocompatibility assessments based on cell viability tests confirmed the potential of these hydrogels as biocompatible materials. By highlighting the significance of developing an HSF/GG dual-crosslinked hydrogel, this study contributes to the advancement of novel double-composite hydrogels with remarkable biocompatibility. Overall, our findings demonstrate the capability of controlling the mechanical properties of hydrogels through molecular weight modulation via hydrolysis and highlight the development of a biocompatible HSF/GG dual-crosslinked hydrogel with potential biomedical applications.

Background/Aim: The aim of this study was to compare clinical features of hypertriglyceridemia-induced acute pancreatitis (HTGAP) with those of biliary acute pancreatitis (BAP) and alcoholic acute pancreatitis (AAP), respectively.Methods: Medical records of patients with acute pancreatitis (AP) who were admitted to our institution from January 2014 to December 2018 were retrospectively reviewed. Disease severity and local complications were evaluated according to the 2012 Revised Atlanta Classification. Systemic complications were evaluated according to the Modified Marshall Scoring System.Results: Of the total 610 patients with AP, those with BAP, AAP, and HTGAP were 310 (50.8%), 144 (23.6%), and 17 (2.8%), respectively. Compared with BAP, HTGAP showed higher proportion of moderately severe acute pancreatitis (MSAP) (64.7% vs. 28.1%, pp pp p =0.140). Contrarily, there was no significant difference between HTGAP and AAP with respect to disease severity (64.7% vs. 63.9% in MSAP and 17.6% vs. 6.9% in SAP, p =0.181), local complications (76.5% vs. 67.4%, p =0.445), recurrence rate (52.9% vs. 32.6%, p =0.096), and systemic complications (23.5% vs. 11.5%, p =0.233).Conclusions: HTGAP showed higher disease severity, more local complications, and higher recurrence rate than BAP. However, there was no significant difference in clinical features between HTGAP and BAP.

The high demand for transplantable corneas is unlikely to subside anytime soon as there is a persistent shortage of cadaveric cornea. The goal of this study was to fabricate film scaffolds with desirable properties of a corneal endothelial cells (CECs) carrier. We used biocompatible materials (curcumin (CC) and silk fibroin (SF)) to construct transparent film scaffolds for CEC regeneration. The film scaffolds were subjected to surface analysis, transparency, stiffness, thermal characterization, and hydrophilicity evaluation. Biological activity of CECs on CC/SF film was analyzed by MTT assay, morphological analysis, mRNA expression, and histological study. Our results showed that the CC/SF film scaffolds had enhanced roughness and transparency compared to the pristine SF film scaffold. The hydrophilicity of the CC/SF film scaffolds showed a topographical environment that encouraged cellular interaction and tissue integration. All the films showed stable thermal characters and an improved capacity for cell growth when a proper amount of CC was incorporated into the SF film scaffolds. The results indicate that a robust scaffold is suitable for CEC transplantation.

Various research about cartilage regeneration using biomaterials has been done recently. Particularly, gellan gum hydrogel (GG) is reported to be suitable as a biomaterial for cartilage tissue engineering (TE) for its water uptaking ability, producibility, and environmental resemblance of native cartilage. Despite these advantages, mechanical and cell adhesion properties are still difficult to modulate. Reinforcement is essential to overcome these problems. Herein, GG was modified by physically blending with different lengths of silk fiber (SF). As SF is expected to improve such disadvantages of GG, mechanical and biological properties were characterized to confirm its reinforcement ability. Mechanical properties such as degradation rate, swelling rate, compression strength, and viscosity were studied and it was confirmed that SF significantly reinforces the mechanical properties of GG. Furthermore, in vitro study was carried out to confirm morphology, biocompatibility, proliferation, and chondrogenesis of chondrocytes encapsulated in the hydrogels. Overall, chondrocytes in the GG blended with SF (SF/GG) showed enhanced cell viability and growth. According to this study, SF/GG can be a promising biomaterial for cartilage TE biomaterial. This article is protected by copyright. All rights reserved.

Introduction Chronic hepatitis B is an important public health concern. Introduction of oral nucleos(t)ide analogs (NAs), inhibitors of hepatitis B virus (HBV) polymerase, was a milestone that lowered the high viral loads associated with an increased risk of liver-related complications. Areas covered Although the currently available NAs are effective in suppressing viral replication, anti-HBV treatment in principle requires lifelong drug administration, and some patients have limitations such as the incidence of liver cancer and the likelihood of toxicities following long-term treatment despite viral suppression. Besifovir dipivoxil maleate (BSV), an oral nucleotide analog, is a prodrug that is metabolized to its active form. It has consistent and well-characterized pharmacokinetics in animals and human. In clinical studies, BSV exhibits significant and potent viral suppression of HBV replication with maintenance of antiviral efficacy for over 192 weeks without resistance, or renal and bone toxicities. Herein, the authors discuss the data of BSV and provide the reader with their expert opinion. Expert opinion BSV is a newly developed antiviral agent against HBV. This new agent has strong antiviral activity with low toxicity and a high barrier to resistance. Because there is concern that patients treated with a high dose of BSV require carnitine supplementation, BSV with carnitine supplementation is recommended during antiviral therapy.

Cell therapies for age-related macular degeneration (AMD) treatment have been developed by integrating hydrogel-based biomaterials. Until now, cell activity has been observed only in terms of the modulus of the hydrogel. In addition, cell behavior has only been observed in the 2D environment of the hydrogel and the 3D matrix. As time-dependent stress relaxation is considered a significant mechanical cue for the control of cellular activities, it is important to optimize hydrogels for retinal tissue engineering (TE) by applying this viewpoint. Herein, a gellan Gum (GG)/Hyaluronic acid (HA) hydrogel was fabricated using a facile physical crosslinking method. The physicochemical and mechanical properties were controlled by forming a different composition of GG and HA. The characterization was performed by conducting a mass swelling study, a sol fraction study, a weight loss test, a viscosity test, an injection force study, a compression test, and a stress relaxation analysis. The biological activity of the cells encapsulated in 3D constructs was evaluated by conducting a morphological study, a proliferation test, a live/dead analysis, histology, immunofluorescence staining, and a gene expression study to determine the most appropriate material for retinal TE biomaterial. Hydrogels with moderate amounts of HA showed improved physicochemical and mechanical properties suitable for injection into the retina. Moreover, the time-dependent stress relaxation property of the GG/HA hydrogel was enhanced when the appropriate amount of HA was loaded. In addition, the cellular compatibility of the GG/HA hydrogel in in vitro experiments was significantly improved in the fast-relaxing hydrogel. Overall, these results demonstrate the remarkable potential of GG/HA hydrogel as an injectable hydrogel for retinal TE and the importance of the stress relaxation property when designing retinal TE hydrogels. Therefore, we believe that GG/HA hydrogel is a prospective candidate for retinal TE biomaterial.

Collagen, with low antigenicity and excellent cell adhesion, is a biomaterial mainly used for regenerating bone, cartilage, and skin, owing to its biocompatibility and biodegradability. Results from a previous study confirmed that a scaffold mixed with duck feet-derived collagen (DC) and Poly(lactic-co-glycolic acid) (PLGA) reduced inflammatory reaction and increased bone regeneration. To develop an optimal bone substitute we included hydroxyapatite (HAp), a key osteoconductive material, in a DC and PLGA mixture. We fabricated 0, 10, 20, 40, 60, and 80 wt% DC/PLGA/HAp scaffolds and studied their potential for bone tissue engineering. Characteristic analysis of the scaffold and seeding of rabbit bone marrow mesenchymal stem cells (rBMSCs) on the scaffold were conducted to investigate cell proliferation, osteogenic differentiation, and bone formation. We confirmed that increasing DC concentration not only improved the compressive strength of the DC/PLGA/HAp scaffold but also cell proliferation and osteogenic differentiation. It was found through comparison with previous studies that including HAp in the scaffold also promotes osteogenic differentiation. Our study thus shows through in vivo results that the 80 wt% DC/PLGA/HAp scaffold promotes bone mineralization and collagen deposition while reducing the inflammatory response. Hence, 80 wt% DC/PLGA/HAp has excellent potential as a biomaterial for bone regeneration applications.

The damage to retinal pigment epithelium (RPE) cells can lead to vision loss and permanent blindness. Therefore, an effective therapeutic strategy has emerged to replace damaged cells through RPE cell delivery. In this study, we fabricated injectable gellan gum (GG)/silk sericin (SS) hydrogels as a cell carrier by blending GG and SS. To determine the appropriate concentration of SS for human RPE ARPE-19, 0, 0.05, 0.1, and 0.5% (w/v) of SS solution were blended in 1% (w/v) GG solution (GG/SS 0%, GG/SS 0.05%, GG/SS 0.1%, and GG/SS 0.5%, respectively). The physical and chemical properties were measured through Fourier-transform infrared spectroscopy, scanning electron microscopy, mass swelling, and weight loss. Also, viscosity, injection force, and compressive tests were used to evaluate mechanical characteristics. Cell proliferation and differentiation of ARPE-19 were evaluated using quantitative dsDNA analysis and real-time polymerase chain reaction, respectively. The addition of SS gave GG/SS hydrogels a compressive strength similar to that of natural RPE tissue, which may well support the growth of RPE and enhance cell proliferation and differentiation. In particular, the GG/SS 0.5% hydrogel showed the most similar compressive strength (about 10 kPa) and exhibited the highest gene expression related to ARPE-19 cell proliferation. These results indicate that GG/SS 0.5% hydrogels can be a promising biomaterial for cell delivery in retina tissue engineering.

Background/Aims: Recent data indicate the presence of liver enzyme abnormalities in patients with coronavirus disease 2019 (COVID-19). We aimed to evaluate the clinical features and treatment outcomes of COVID-19 patients with abnormal liver enzymes. Methods: We performed a retrospective, multicenter study of 874 COVID-19 patients admitted to five tertiary hospitals from February 20 to April 14, 2020. Data on clinical features, laboratory parameters, medications, and treatment outcomes were collected until April 30, 2020, and compared between patients with normal and abnormal aminotransferases. Results: Abnormal aminotransferase levels were observed in 362 patients (41.1%), of which 94 out of 130 (72.3%) and 268 out of 744 (36.0%) belonged to the severe and non-severe COVID- 19 categories, respectively. The odds ratios (95% confidence interval) for male patients, patients with a higher body mass index, patients with severe COVID-19 status, and patients with lower platelet counts were 1.500 (1.029 to 2.184, p=0.035), 1.097 (1.012 to 1.189, p=0.024), 2.377 (1.458 to 3.875, p=0.001), and 0.995 (0.993 to 0.998, p>0.001), respectively, indicating an independent association of these variables with elevated aminotransferase levels. Lopinavir/ ritonavir and antibiotic use increased the odds ratio of abnormal aminotransferase levels after admission (1.832 and 2.646, respectively, both p

This study shows tunable stress relaxing gellan gum (GG) hydrogel for enhanced cell growth and regenerative medicine. The molecular weight and physical crosslinking density of GG were tuned and characterized with physicochemical analysis and mechanical tests. The result showed that a decrease in the molecular weight of the GG correlated with a decline in the mechanical properties but faster stress relaxing character. We also discovered that human-derived bone marrow stem cells (hBMSC) showed active viability, proliferation, and remodeling in the fast stress relaxing GG hydrogel. In particular, hBMSC showed an enhanced release profile of growth factors and exosomes (Exo) in the fast stress relaxing GG hydrogel. The secretome obtained from hBMSC embedded in hydrogel exhibited similar cytotoxicity and wound healing properties to that of secretome extracted from hBMSC cultured in a tissue culture plate (TCP) a standard culture condition. Thus, this work demonstrates the potential of fast stress relaxing GG hydrogels for medical application.

Acetaminophen (paracetamol, APAP) is a major component of Tylenol, Penzal Q, and Panpyrin, and is the most commonly used antipyretic analgesic in children. The conventional oral drug delivery systems of APAP are pills and tablets. However alternative drug delivery methods are desirable in case of pediatric or geriatric patients, especially for drugs like APAP that must be taken in large doses at once. Another requirement for a good drug delivery system is the rapid dissolution to ensure a rapid therapeutic action as pain reliever. In this study Acetaminophen (paracetamol, APAP) was encapsulated in a water-soluble polymer. After the preparation of the solid dispersion by encapsulating acetaminophen in polyvinylpyrrolidone, the resultant granules were used in three formulations: tablets, chewable tablets, and oral dissolving films (ODF). Solid dispersions and prepared formulations were evaluated by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffractometer (XRD), and universal tensile machine (UTM), and the release behavior was compared. As a result, it was confirmed that the oral dissolving films can be taken easily because it has the advantages of both tablet and liquid dosage form accurate dosage, easy administration, easy swallowing, and fast bioavailability. Furthermore, the drug absorption rate can be effectively increased by changing the formulation.

Articular hyaline cartilage is an extremely hydrated, not vascularized tissue with a low-cell density. The damage of this tissue can occur after injuries or gradual stress and tears (osteoarthritis), minor damages can be self-healed in several weeks, but major injuries may eventually require surgery. In fact, in this case, because of nature of the cartilage (the absence of cells and vascularization) it is difficult to expect its natural regeneration in a reasonable amount of time. In recent years, cell therapy, in which cells are directly transplanted, has attracted attention. In this study, a scaffold for implanting chondrocytes was prepared. The scaffold was made as a sponge using the eggshell membrane and agarose. The eggshell membrane is structurally similar to the extracellular matrix and nontoxic due to its many collagen components and has good biocompatibility and biodegradability. However, scaffolds made of collagen only has poor mechanical properties. For this reason, the disulfide bond of collagen extracted from the insoluble eggshell membrane was cut, converted into water-soluble, and then mixed with agarose to prepare a scaffold. Agarose is capable of controlling mechanical properties, has excellent biocompatibility, and is suitable for forming a hydrogel having a three-dimensional porosity. The scaffold was examined for Fourier-transform infrared, mechanical properties, biodegradability, and biocompatibility. In in vitro experiment, cytotoxicity, cell proliferation, and messenger RNA expression were investigated. The study demonstrated that the agarose/eggshell membrane scaffold can be used for chondrocyte transplantation.

Patients at risk for hypertension with comorbidities such as diabetes and metabolic syndrome often require two or more antihypertensive drugs to lower their blood pressure. Telmisartan and amlodipine are widely known drugs to treat hypertension. However, telmisartan suffer of poor solubility in water that makes necessary to increase its dosage to reach a sufficient therapeutic concentration. In this study, a solid dispersion containing a water-soluble polymer was prepared to make the absorption rate of telmisartan similar to that of amlodipine, a water soluble drug. As water-soluble polymers, polyvinylpyrrolidone K30, polyethylene glycol 6000, and poloxamer 407 were used. The encapsulation of the solid dispersion was analyzed by differential scanning calorimetry, Xray diffraction, and high-performance liquid chromatography. The reduced flowability of the solid dispersion was improved by a wet granulation. Scanning Electron Microscopy was used to study the morphology and the flowability was verified by measuring the angle of repose, bulk density, and tap density, and expressed by Hausner ratio and Carr index. The release behavior was confirmed by dissolution test and high-performance liquid chromatography. As result we proved that telmisartan a higher release rate when encapsulated with PVP K30. Finally, we designed a drug formulation in which amlodipine and telmisartan could be absorbed at a similar rate.

In this study, dopamine-functionalized gellan gum (DFG) hydrogel was prepared as a carrier for retinal pigment epithelium (RPE) cell delivery via a carbodiimide reaction. The carboxylic acid of gel...

Bone is the rigid tissue that constitutes the skeleton. The material for bone regeneration has to provide the mechanical stability by maintaining the mechanical loads both in the rest conditions and during the body movements. Bone is dynamic tissue constantly reshaped by the action of cells (osteoblasts and osteoclasts). This activity is normally enough to heal bone injuries; however, in several conditions, when bone is subjected to fatal damages, self-renewal is difficult, if not even impossible, and a medical treatment is required. The transplantation of a biomaterial is one of the common surgical procedures to overcome critical injuries. In this study, we exploited the effect of the use of different sources of demineralized bone powder (DBP) in combination with gellan gum (GG) to form a GG-DBP hydrogel scaffold with the purpose of regenerating the bone tissue. DBP was extracted from the femurs of two typologies of

Herein, gellan gum (GG), a nature-derived polysaccharide, was applied to combine fluorescein isothiocyanate (FITC) to fabricate a bio-imaging material. The synthesis process of the FITC grafted GG (GG-F) and manufacturing method of GG-F scaffolds are presented. Chemical, physicochemical, and mechanical properties were characterized. In vitro study and in vivo study by implanting the GG-F scaffolds under the subcutaneous area of the nude mice were carried out to verify biocompatibility and safety of the material. The emission of the FITC was confirmed with high-resolution confocal laser scanning microscope (SR CLMS) and fluorescence in vivo imaging (FOBI). The results exhibited well-synthesized GG-F and the manufactured GG-F scaffolds showed similar property of GG scaffolds which confirms that the chemical modification does not affect the property of GG scaffolds. The in vitro and in vivo study exhibited biocompatibility of the GG-F material. Overall, the properly blended GG-F in GG did not influence the characteristics of the pristine GG except for the chemical property. Therefore, the GG-F can be applied for the future analysis in verifying the mechanism of GG characters and can be a promising candidate for bio-imaging.

In this study, 6-(6-aminohexyl) amino-6-deoxy-β-cyclodextrin-gellan gum complex hydrogel (HCD-GG) was developed to enhance the affinity of anti-inflammatory drug dexamethasone (Dx), improve chondrogenesis, and decrease the inflammatory response. The modified chemical structure was confirmed by NMR and FTIR. Mechanical and physicochemical properties were characterized by performing viscosity study, compression test, injection force test, swelling kinetic, weight loss, and morphological study. The release profile of the drug-loaded hydrogels was analyzed to confirm the affinity of the hydrophobic drugs and the matrix and characterize cumulative release. In vitro test was carried out with MTT assay, live/dead staining, glycosaminoglycan (GAGs) content, double-stranded DNA (dsDNA) content, morphological analysis, histology, and gene expression. In vivo experiment was conducted by implanting the samples under a subcutaneous area of SPD rat and cartilage defected rabbit model. The results displayed successfully synthesized HCD-GG. The gelation temperature of the modified hydrogels was decreased while the mechanical property was improved when the drug was loaded in the modified hydrogel. Swelling and degradation kinetics resulted in a higher level compared to the pristine GG but was a sufficient level to support drugs and cells. The affinity and release rate of the drug was higher in the HCD-GG group which shows an improved drug delivery system of the GG-based material. The microenvironment provided a suitable environment for cells to grow. Also, chondrogenesis was affected by the existence of Dx and microenvironment, resulting in higher expression levels of cartilage-related genes while the expression of the inflammation mediators decreased when the Dx was loaded. In vivo study showed an improved anti-inflammatory response in the drug-loaded hydrogel. Furthermore, the cartilage defected rabbit model showed an enhanced regenerative effect when the Dx@HCD-GG was implanted. These results suggest that HCD-GG and Dx@HCD-GG have the potential for cartilage regeneration along with multiple applications in tissue engineering and regenerative medicine.

In this experiment, hydrogel composite was developed with gellan gum (GG) and platelet-rich plasma (PRP) to induce chondrogenesis of adipose-derived stem cells (ADSCs) in the hydrated environment. FTIR, SEM, and compression test were carried out to characterize the fabricated material. Biocompatibility was analyzed by MTT assay. The morphology of the encapsulated ADSCs was observed under SEM. Chondrogenesis was examined by PCR. The chemical and morphological analysis displayed the appearance of PRP in the matrix. The mechanical property of the hydrogel decreased as the PRP was loaded but viability and chondrogenesis were significantly increased with the proper amount of the PRP. Overall, the composite of the appropriate incorporation of PRP in the GG can enhance the microenvironment for chondrogenesis and expected to have great potential in tissue engineering.

Herein, a facile macro- and microporous polycaprolactone/duck's feet collagen scaffold (PCL/DC) was fabricated and characterized to confirm its applicability in bone tissue engineering. A biomimetic scaffold for bone tissue engineering and regeneration for bone defects is an important element. PCL is a widely applied biomaterial for bone tissue engineering due to its biocompatibility and biodegradability. However, the high hydrophobicity and low cell attachment site properties of PCL lead to an insufficient microenvironment in designing a scaffold. Collagen is a nature-derived biomaterial that is widely used in tissue engineering and has excellent biocompatibility, mechanical properties, and cell attachment moieties. Among the resources from which collagen can be obtained, DC contains a high amount of collagen type I (COL1), is biocompatible, and is cost-effective. In this study, the scaffolds were fabricated by blending DC with PCL in various ratios and applied non-solvent-induced phase separation (NIPS) and thermal-induced phase separation (TIPS) (N-TIPS), solvent casting and particulate leaching (SCPL), and gas foaming method to fabricate macro- and microporous structure. The characterization of the fabricated scaffolds was carried out by morphological analysis, bioactivity test, physicochemical analysis, and mechanical test.

Background/Aims: Although coronavirus disease 2019 (COVID-19) has spread rapidly worldwide, the implication of pre-existing liver disease on the outcome of COVID-19 remains unresolved.Methods: A total of 1,005 patients who were admitted to five tertiary hospitals in South Korea with laboratory-confirmed COVID-19 were included in this study. Clinical outcomes in COVID-19 patients with coexisting liver disease as well as the predictors of disease severity and mortality of COVID-19 were assessed.Results: Of the 47 patients (4.7%) who had liver-related comorbidities, 14 patients (1.4%) had liver cirrhosis. Liver cirrhosis was more common in COVID-19 patients with severe pneumonia than in those with non-severe pneumonia (4.5% vs. 0.9%, P=0.006). Compared to patients without liver cirrhosis, a higher proportion of patients with liver cirrhosis required oxygen therapy; were admitted to the intensive care unit; had septic shock, acute respiratory distress syndrome, or acute kidney injury; and died (PP=0.003). Along with old age and diabetes, the presence of liver cirrhosis was found to be an independent predictor of severe disease (odds ratio, 4.52; 95% confidence interval [CI], 1.20–17.02;P=0.026) and death (hazard ratio, 2.86; 95% CI, 1.04–9.30; P=0.042) in COVID-19 patients.Conclusions: This study suggests liver cirrhosis is a significant risk factor for COVID-19. Stronger personal protection and more intensive treatment for COVID-19 are recommended in these patients.

Hydrogels have a large amount of water that provides a cartilage-like environment and is used in tissue engineering with biocompatibility and adequate degradation rates. In order to differentiate stem cells, it is necessary to adjust the characteristics of the matrix such as stiffness, stress-relaxing time, and microenvironment. Double network (DN) hydrogels provide differences in cellular biological behavior and have interpenetrating networks that combine the advantages of the components. In this study, by varying the viscous substrate of pullulan (PL), the DN hydrogels of gellan gum (GG) and PL were prepared to determine the cartilage differentiation of bone marrow stem cell (BMSC). The characteristics of GG/PL hydrogel were investigated by examining the swelling ratio, weight loss, sol fraction, compressive modulus, and gelation temperature. The viability, proliferation, and toxicity of BMSCs encapsulated in hydrogels were evaluated. Cartilage phenotype and cartilage differentiation were confirmed by morphology, GAG content, and cartilage-specific gene expression. Overall results demonstrate that GG/PL hydrogels can form cartilage differentiation of BMSCs and can be applied for tissue engineering purposes.

Gellan gum (GG), a nature-derived polysaccharide, is one of the materials widely used in cartilage tissue engineering (TE). Glycol chitosan (GC), a derivative of chitosan, is a water-soluble natural polymer that has excellent biocompatibility and biodegradability as well as cell adhesion. Herein, GG was physically blended with GC to enhance the mechanical properties and microenvironment of the GG to apply in cartilage TE. The study was conducted with a hydrogel model which is similar to the extracellular matrix (ECM) of cartilage tissue. The physicochemical studies were carried out with morphological study, swelling ratio, weight loss, and sol fraction. The mechanical characterization was conducted with compression test and rheological study to confirm availability in cartilage TE material. Furthermore, in vitro studies such as morphology investigation, viability assay, GAG content, qRT-PCR, and histological study were performed to verify biocompatibility and chondrogenesis of the material. The mechanical and biological properties improved with a proper amount of GC. Overall results verify the potential of the material and can be further used for the cartilage TE.

The cellular transplantation approach to treat damaged or diseased retina is limited because of poor survival, distribution, and integration of cells after implantation to the sub-retinal space. To overcome this, it is important to develop a cell delivery system. In this study, a ternary hydrogel of gelatin (Ge)/gellan gum (GG)/glycol chitosan (CS) is suggested as a cell carrier for retinal tissue engineering (TE). Physicochemical properties such as porosity, swelling, sol fraction, and weight loss were measured. The mechanical study was performed with compressive strength and viscosity to confirm applicability in retinal TE. An

Hyaluronic acid (HA) is one of the most applied biomaterials in a tissue engineering field due to its biocompatibility and its presence in the native extracellular matrix (ECM) of tissues. However, the mechanical property of the HA is weak and requires specific treatment to improve its properties. The application of Agarose (AG) hydrogel is widely studied and used as a support for the three-dimensional culture of cells due to its biocompatibility. Nevertheless, AG itself lacks the biological environment of the matrix which is unsuitable for the growth of the encapsulated cells. In this study, the composite of HA hydrogel and AG hydrogel (HA/AG hydrogel) is proposed to supplement the drawbacks of each hydrogel. HA provided enhanced microenvironment of matrix and AG improved the mechanical properties and assisted the cells. The characterization of the blended hydrogels was carried out with FT-IR, weight loss, swelling ratio, and compressive strength study. The biocompatibility and biological environment of the composite was evaluated by dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide; thiazolyl blue (MTT), live/dead staining, and morphological study. The composite biomaterial exhibited applicability for cartilage tissue engineering and the in vitro study of the cell-laden HA/AG hydrogel displayed potential for cartilage tissue engineering in the future.

In this study, silk fibroin microfiber (mSF) was applied to assist spheroid assemblies of rBMSCs (rabbit bone marrow stem cells) (S/B). Alkaline hydrolysis was induced with different times and conditions to manufacture the various sizes of mSF. The mSF was incorporated in the rBMSC with different amounts to optimize proper content for spheroid assembly. The formation of the S/B was confirmed under optical microscopy and SEM. Proliferation and viability were characterized by CCK-8 and live/dead staining. Osteogenesis was analyzed with ALP (alkaline phosphatase) activity studies and real-time polymerase chain reaction. The S/B was successfully produced and displayed uniformly distributed cells and mSF with the presence of a gap in the structure. Proliferation and viability of the S/B significantly increased when compared to rBMSC spheroids (B), which is potentially due to the enhanced transportation of oxygen and nutrients to the cells located in the core region. Additionally, ALP activity and osteogenic markers were significantly upregulated in the optimized S/B under osteogenic media conditions. Overall, a hybrid–spheroid system with a simple 3D cell culture platform provides a potential approach for engineering therapeutic stem cells.

Nifedipine is a calcium channel blocker widely used for the treatment of blood pressure related diseases such as angina, hypertension and Raynaud. However, since the drug after the administration reaches the highest blood concentration between 30 min and 2 h, its insolubility may expose the patient to various side effects. In this study, nifedipine was prepared as a solid dispersion using a water-soluble polymer (PVP-K30) in order to increase the releasing time and postpone the time at which the drug reaches its highest concentration, thereby increasing its bioavailability. SEM, XRD, DSC, and FT-IR were used for characterization of the solid dispersion. In order to test the release of the drug, a dissolution test was performed with a serous fluid for 12 h. In this work a drug formulation capable of sustained release of nifedipine using a water-soluble polymer was developed.

Osteochondral (OC) lesions can occur in the knee and ankle. Such lesions induce a fracture in the cartilage protecting the bone joints. Cartilage tissue shows limited self-regeneration ability, hence the tissue is avascular and lack of vascular innervation, while the bone is a unique organ with the capacity to self-repair of small defects. In this present study, we have prepared a scaffold using demineralized bone powder (DBP) extracted from Gallus gallus var domesticus (GD), and Gellan gum (GG) for OC tissue regeneration. They were characterized for their chemical, physical, mechanical and biological properties using different available techniques, in vitro bioactivity was performed in simulated body fluid for 14 days confirming the formation of bone-like apatite. The in vitro biocompatibility was analyzed using chondrocyte cells and osteogenic and chondrogenic marker gene expression using RT-PCR, in vivo experiments performed by implanting scaffold in rabbit and characterized by histology and immunofluorescent stainings. The obtained results indicated that the prepared pores scaffold was biocompatible, and promote OC regeneration and integration of newly formed tissues with the host tissues in a rabbit. The prepared 1% DBP/GG scaffold can be used as a potential and promising alternate material for OC regeneration.

Bone defects are usually difficult to be regenerated due to pathological states or the size of the injury. Researchers are focusing on tissue engineering approaches in order to drive the regenerative events, using stem cells to regenerate bone. The purpose of this study is to evaluate the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) on biologically derived Gallus gallus domesticus-derived demineralized bone particle (GDD) sponge. The sponges were prepared by freeze-drying method using 1, 2, and 3 wt% GDD and cross-linked with glutaraldehyde. The GDD sponge was characterized using scanning electron microscopy, compressive strength, porosity, and Fourier transform infrared. The potential bioactivity of the sponge was evaluated by osteogenic differentiation of BMSCs using 3(4, dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and quantifying alkaline phosphatase (ALP) activity. in vivo experiments were evaluated through a micro-computerized tomography (μ-CT) and histological assays. The analysis confirmed that an increase in the concentration of the GDD in the sponge leads to a higher bone formation and deposition in rat calvarial defects. Histological assay results were in line with μ-CT. The results reported in this study demonstrated the potential application of GDD sponges as osteoinductor in bone tissue engineering in pathological or nonunion bone defects.

Omeprazole (OM), typically used for patients with gastric problems, is a proton pump inhibitor, which reduces the amount of stomach acid production effectively by regulating the proton pump. However, the main side effect of OM is the calcium indigestion, which may cause the calcium deficiency in the long term. Seaweeds are abundant in calcium (approximately 560–1200 mg per 100 g) and nutrients such as vitamins (approximately 150–400 mg per 1 kg) and minerals. In particular, high level of magnesium in the seaweed can assist the absorption of calcium. Accordingly, seaweeds can be a good source of nutrients to support OM therapy. Herein, we produced a solid dispersion (SD) which is composed of OM and seaweed calcium (SC) and can be suitable for the oral treatment, via the ultra-multiple crystal method. We also optimized the film formulation so that the SD could be absorbed quickly and efficiently by the oral cavity. Due to many advantages of using the oral thin film (OTF), we chose to fabricate OTF with our optimized dispersion method. OTF allows for both the rapid and efficient dissolution within the oral cavity and the protection of the active ingredient (i.e., OM) from rapid degradation under acidic conditions. The prepared SD samples were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). Thermal analysis of SD was conducted by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Hydrophobicity of SD was evaluated by the contact angle. Furthermore, the dissolution test and the HPLC analysis of SD were performed.

Cu