Decellularization Techniques for Tissue Engineering: Towards Replicating Native Extracellular Matrix Architecture in Liver Regeneration.

The process of tissue regeneration requires the utilization of a scaffold, which serves as a structural framework facilitating cellular adhesion, proliferation, and migration within a physical environment. The primary aim of scaffolds in tissue engineering is to mimic the structural and functional properties of the extracellular matrix (ECM) in the target tissue. The construction of scaffolds that accurately mimic the architecture of the extracellular matrix (ECM) is a challenging task, primarily due to the intricate structural nature and complex composition of the ECM. The technique of decellularization has gained significant attention in the field of tissue regeneration because of its ability to produce natural scaffolds by removing cellular and genetic components from the extracellular matrix (ECM) while preserving its structural integrity. The present study aims to investigate the various decellularization techniques employed for the purpose of isolating the extracellular matrix (ECM) from its native tissue. Additionally, a comprehensive comparison of these methods will be presented, highlighting their respective advantages and disadvantages. The primary objective of this study is to gain a comprehensive understanding of the anatomical and functional features of the native liver, as well as the prevalence and impact of liver diseases. Additionally, this study aims to identify the limitations and difficulties associated with existing therapeutic methods for liver diseases. Furthermore, the study explores the potential of tissue engineering techniques in addressing these challenges and enhancing liver performance. By investigating these aspects, this research field aims to contribute to the advancement of liver disease treatment and management.

Assessment of various forms of cellulose-based Luffa cylindrica (mat, flakes and powder) reinforced polydimethylsiloxane composites for oil sorption and organic solvents absorption.

Oil spillage has damaged public health noticeably and contributed to significant environmental deterioration. As a result, a significant amount of effort has been spent on investigating and developing the sorbent materials capable of separating oil from water. Thus, the sorbent materials that could be effective particularly in oil spill disposal and resolve such environmental issue remain to be explored. We have proposed luffa cylindrica (LC)-polydimethylsiloxane (PDMS) composite forms to remove the oil and organic components that might be hazardous to aquatic organisms. The scaffolds were fabricated using hand lay-up method with various forms of luffa cylindrica i.e., LC mat, flakes and powder. Various characterizations such as scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), effective porosity, surface wettability, mechanical stability, cytotoxicity and sorption behavior with respect to oil, phosphate buffer saline (PBS) and few organic solvents were performed. The results showed that the scaffold in combination with P-L flakes was highly effective in eradicating oil spills and removing harmful components of crude oil. Scaffolds composed of P-L mat, P-L flakes, P-L powder, and PDMS (P) exhibited oil absorption efficacy around 16.09 ± 4.62 %, 24.49 ± 3.55 %, 15.52 ± 2.67 % and 5.52 ± 1.44 %, respectively. We anticipate that the proposed scaffolds have the tremendous potential to provide a solution to this significant environmental remediation issue and to serve as a cost-effective method for removing oil spills and hazardous crude oil components.

Effects of ELF-PEMF exposure on spontaneous alternation, anxiety, motor co-ordination and locomotor activity of adult wistar rats and viability of C6 (Glial) cells in culture.

The effects of ELF-PEMF exposure on spontaneous alternation, anxiety, motor coordination, and locomotor activity have been discussed in various pre-clinical and clinical settings. Several epidemiological and experimental studies have demonstrated the potential effects of ELF-PEMF when exposed > âˆ¼1 h/day; however, very few studies have focused on understanding the influence of ELF-PEMF exposure of 1-3 mT with an exposure duration of < 1 h/day on spontaneous alternation, anxiety, motor coordination, and locomotor activity. Hence, we attempted to study the effects of ELF-PEMF exposure of 1-3 mT, 50 Hz with an exposure duration of 20 min each with a 4 h gap (2 times) on the cellular proliferation and morphologies of C6 (Glial) cells and spontaneous alternation, anxiety, motor coordination and locomotor activity of Wistar rats under in vitro and in vivo conditions, respectively. The results showed that ELF-PEMF exposure did not induce any significant levels of cellular fragmentation and changes in the morphology of glial cells. Also, the outcomes revealed no noticeable effects on spontaneous alternation, anxiety, motor coordination, and locomotor activity in PEMF-exposed groups compared with the control. No undesirable side effects were observed at the highest dose (B=3 mT). We also performed histological analysis of the selected brain sections (hippocampus and cortex) following ELF-PEMF exposure. Incidentally, no significant changes were observed in cortical cell counts, tissue structure, and morphology.

Fabrication and in vitro characterization of luffa-based composite scaffolds incorporated with gelatin, hydroxyapatite and psyllium husk for bone tissue engineering.

Bone tissue engineering is an emerging technology that has been developed in recent years to address bone abnormalities by repairing, regenerating and replacing damaged/injured tissues. In present work, we report the fabrication and characterization of porous luffa-based composite scaffolds composed of Luffa cylindrica (sponge gourd) powder (LC)/hydroxyapatite (HA), psyllium husk (PH) and gelatin (G) in various combinations (w/v) i.e. 3% LC, 5% LC and control (C) (without luffa powder) by using freeze-drying method. The structural stability of the scaffolds was obtained after chemically crosslinking them with glutaraldehyde (GTA), which was identified via scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The hydrophilic behavior of the samples was quantified by water contact angle measurements. The average pore size of the scaffolds was observed in a range of 20-240 µm. As per the obtained data, the apparent and effective porosities were estimated as ∼57.08 ± 4.38%, ∼50.58 ± 4.09%, ∼59.45 ± 1.60% and 51.37 ± 3.36%, 47.94 ± 4.57% and 53.09 ± 5.45% for 3% LC, 5% LC and control (C) scaffolds, respectively. The scaffolds were found to be noticeably stable for 50 days at 37 °C in a lysozyme solution. The liquid retention capacity of the scaffolds revealed that the luffa-based scaffolds gained lower retention capacity compared to the control (C) scaffold; indicating an increase in scaffold stiffness due to the addition of luffa. Compressive strength study demonstrated that the mechanical stability of the fabricated luffa-based scaffolds got increased significantly from ∼1.5 to ∼9.5 MPa, which is comparable to that of trabecular bone. In addition, proliferation and viability analysis of MG-63 osteoblast-like cells revealed a significant level of cellular compatibility i.e. approaching ∼64% proliferation by 6th day in vitro compared to control. Thus, the obtained results demonstrate that the fabricated novel luffa-based scaffolds exhibit good cytocompatibility, remarkable porosity and excellent mechanical strength comparable to native human bone. Therefore, we anticipate that the developed luffa-based scaffolds could be a promising candidate for bone tissue engineering applications.

Revisiting Methodologies for In Vitro Preparations of Advanced Glycation End Products.

Chronic elevation of sugar and oxidative stress generally results in development of advanced glycation end products (AGEs) in diabetic individuals. Accumulation of AGEs in an individual can give rise to the activation of several pathways that will ultimately lead to various complications. Such AGEs can also be prepared in an in vitro environment. For an in vitro preparation of advanced glycation end products (AGEs), proteins, lipids, or nucleic acids are generally required to be incubated with reducing sugars at a physiological temperature or higher depending upon the protocol optimized for its preparation. Certain other factors are also optimized and added to the buffer to hasten its preparation or alter the properties of prepared AGEs. Through this review, we intend to highlight the various studies related to the experimental procedures for the preparation of different types of AGEs. In addition, we present the comparative study of methodologies optimized for the preparation of AGEs.

Freeze-Thaw-Induced Physically Cross-linked Superabsorbent Polyvinyl Alcohol/Soy Protein Isolate Hydrogels for Skin Wound Dressing: In Vitro and In Vivo Characterization.

In this work, polyvinyl alcohol (PVA)- and soy protein isolate (SPI)-based scaffolds were prepared by physical cross-linking using the freeze-thaw method. The PVA/SPI ratio was varied to examine the individual effects of the two constituents. The physicochemical properties of the fabricated scaffolds were analyzed through Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The SPI concentration significantly affected the properties of scaffolds, such as the extent of gelation (%), pore size, porosity, degradation, swelling, and surface wettability. The in vitro degradation of fabricated hydrogels was evaluated in phosphate-buffered saline and lysozyme solution for a duration of 14 days. The in vitro compatibility of prepared hydrogels was evaluated by the MTT assay with NIH-3T3 cells (fibroblast). The water vapor transmission rate (WVTR) assays showed that all hydrogels possessed WVTR values in the range of 2000-2500 g m-2 day-1, which is generally recommended for ideal wound dressing. Overall, the obtained results reveal that the fabricated scaffolds have excellent biocompatibility, mechanical strength, porosity, stability, and degradation rate and thus carry enormous potential for tissue engineering applications. Furthermore, a full-thickness wound healing study performed in rats supported them as a promising wound dressing material.

Fabrication and Characterization of Silk Fibroin-Based Nanofibrous Scaffolds Supplemented with Gelatin for Corneal Tissue Engineering.

Tissue engineering is a promising approach to overcome the severe worldwide shortage of healthy donor corneas. In this work, we have developed a silk-gelatin composite scaffold using electrospinning and permeation techniques to achieve the properties comparable to cornea analog. In particular, we present the fabrication and comparative evaluation of the novel gelatin sheets consisting of silk fibroin nanofibers, which are prepared using silk fibroin (SF) (in formic acid) and SF (in aqueous) electrospun scaffolds, for its suitability as corneal stromal analogs. All the fabricated samples were treated with ethanol vapor (T) to physically crosslink the silk nanofibers. Micro/nano-scale features of the fabricated scaffolds were analyzed using scanning electron microscopy micrographs. Fourier transform infrared spectroscopy revealed characteristic peaks of polymeric functional groups and modifications upon ethanol vapor treatment. Transparency of the scaffolds was determined using UV-visible spectra. Among all the fabricated samples, the gelatin-permeated SF (in formic acid; T) scaffold showed the highest level of transparency, i.e., 77.75 ± 2.3%, which is similar to that of the native cornea (∼70%-90% [variable with age group]) with healthy acute vision. Contact angle of the samples was studied to estimate the hydrophilicity of the scaffolds. All the scaffolds except non-treated SF (in aqueous; NT) were found to be significantly stable up to 14 days when incubated in phosphate buffered saline at 37°C. Treated samples showed significantly better stability, both physically and microscopically, in comparison to nontreated samples. Proliferation and viability assays of rabbit corneal fibroblast cells (SIRC) and mouse fibroblast cells (L929 RFP) when cultured on fabricated scaffolds revealed remarkable cellular compatibility with gelatin-permeated SF (in formic acid; T) scaffolds compared to SF (in aqueous; T). Unlike other reports in the existing literature, this work presents the design and development of a nanofibrous silk-gelatin composite that exhibits acceptable transparency, cellular biocompatibility, as well as improved mechanical stability comparable to that of native cornea. Therefore, we anticipate that the fabricated novel scaffold is likely to be a good candidate for corneal tissue construct. Moreover, among the fabricated scaffolds, the outcomes depict gelatin-permeated SF (in formic acid; T) composite scaffold to be a better candidate as a corneal stromal analog that carries properties of both the silk and gelatin, i.e., optimal transparency, better stability, and enhanced cytocompatibility.

Printability assessment of psyllium husk (isabgol)/gelatin blends using rheological and mechanical properties.

The primary goal of this study is to highlight the rheological and mechanical properties of a new blend composed of naturally-derived hydrogel materials- psyllium husk (PH) and gelatin (G) for its potential use in three-dimensional (3D) printing technology. The mixtures were prepared at various weight ratios of 100PH, 75PH + 25G and 50PH + 50G. A suitable selection of the printable ink was made based on the preliminary screening steps of manual filament drop test and layer stacking by 3D printing. Printing of the common features such as hexagon and square grids helped evaluating shape fidelity of the chosen ink. Although 50PH + 50G blend was found meeting most of the criteria for an ideal 3D printable ink, rheological and mechanical characterizations have been performed for all the ratios of polymeric blends. This study documents the correlation between various factors of rheology that should be taken into account while categorizing any biomaterial as a printable ink. Yield stress was measured as 18.59 ± 4.21 Pa, 268.74 ± 13.56 Pa and 109.16 ± 9.85 Pa for 50PH + 50G, 75PH + 25G and 100PH, respectively. Similarly, consistency index (K) and flow index (n) were calculated using the power law equation and found as 49.303 ± 4.17, 530.59 ± 10.92, 291.82 ± 10.53 and 0.275 ± 0.04, 0.05 ± 0.005, 0.284 ± 0.04 for 50PH + 50G, 75PH + 25G and 100PH, respectively. The loss modulus (G″) was observed dominating over storage modulus (G') for 50PH + 50G, that depicts its liquid-like property; whereas storage modulus (G') was found dominating in case of 75PH + 25G and 100PH, indicating their solid-like characteristics. In addition, the loss tangent value (tan δ) of 50PH + 50G was observed exceeding unity (1.05), supporting its plastic behavior, unlike 75PH + 25G (0.5) and 100PH (0.33) whose loss tangent values were estimated less than unity revealing their elastic behavior. Also, 50PH + 50G was found to have the highest mechanical strength amongst the three blends with a Young's modulus of 9.170 ± 0.0881 kPa.

Soy protein isolate supplemented silk fibroin nanofibers for skin tissue regeneration: Fabrication and characterization.

Biocompatible soy protein isolate/silk fibroin (SPI/SF) nanofibrous scaffolds were successfully fabricated through electrospinning a novel protein blend SPI/SF. Prepared nanofibers were treated with ethanol vapor to obtain an improved water-stable structure. Fabricated scaffolds were characterized through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), UV-VIS spectrophotometry and image analysis. The mean diameters of SPI/SF electrospun fibers were observed ranging between 71 and 160 nm. The scaffolds were found significantly stable for a prolong duration at the room temperature as well as at 37 °C, when placed in phosphate buffered saline, nutrient medium, and lysozyme-containing solution. The potential of fabricated scaffolds for skin tissue regeneration was evaluated by in vitro culturing of standard cell lines i.e., fibroblast cells (L929-RFP (red fluorescent protein) and NIH-3T3) and melanocytes (B16F10). The outcomes revealed that all the fabricated nanofibrous scaffolds were non-toxic towards normal mammalian cells. In addition, healing of full-thickness wound in rats within 14 days after treatment with a nanofibrous scaffold demonstrated its suitability as a potential wound dressing material. Interestingly, we found that nanofibers induced a noticeable reduction in the proliferation rate of B16F10 melanoma cells.

Fabrication and Cytocompatibility Evaluation of Psyllium Husk (Isabgol)/Gelatin Composite Scaffolds.

Psyllium husk or isabgol contains xylan backbone linked with arabinose, rhamnose, and galacturonic acid units (arabinoxylans). In this study, we demonstrate the fabrication and characterization of a macroporous three-dimensional (3D) composite scaffold by mixing psyllium husk powder (PH) and gelatin (G) in different ratios, viz.100 PH, 75/25 PH/G, and 50/50 PH/G (w/w), using an EDC-NHS coupling reaction followed by freeze-drying method. The reaction was performed in aqueous as well as in alcoholic media to determine the most appropriate solvent system for this purpose. The mechanical strength of the scaffold system was improved from 151 to 438 kPa. The fabricated scaffolds exhibited enhanced structural stability, remarkable swelling capacity, and escalated cell growth and proliferation. ATR-FTIR analysis showed the presence of amide and ester bonds indicating covalent crosslinking. SEM micrographs revealed the porous nature of the scaffolds with pores ranging from 30 to 150 µm, and further pore size distribution curve indicated that 75/25 PH/G (w/w%) EDC-NHS-alcohol scaffold exhibited the best fit to the Gaussian distribution. Swelling capacity of the 100 PH EDC-NHS-alcohol scaffolds was found to be nearly 40% from its original weight in 48 h. MTT assay using fibroblast cells revealed ~ 80% cellular proliferation by 6th day within the fabricated scaffolds in comparison to control. Graphical Abstract ᅟ.

Culturing melanocytes and fibroblasts within three-dimensional macroporous PDMS scaffolds: towards skin dressing material.

In the present study, we propose a platform for topical wound dressing material using a polydimethylsiloxane (PDMS) scaffold in order to enhance the skin healing process. In vitro co-culture assessment of epidermal-origin mouse B16-F10 melanocyte cells and mouse L929 fibroblast cells in three-dimensional polymeric scaffolds has been carried out towards developing bio-stable, interconnected, highly macroporous, PDMS based tissue-engineered scaffolds, using the salt leaching method. To determine a suitable ratio of salt to PDMS pre-polymer in the scaffold, two different samples with ratios 2:1 and 3:1 [w/w], were fabricated. Effective pore sizes of both scaffolds were observed to lie in the desirable range of 152-165 µm. In addition, scaffolds were pre-coated with collagen and investigated as a podium for culturing the chosen cells (fibroblast and melanocyte cells). Experimental results demonstrate not only a high proliferative potential of the skin tissue-specific cells within the fabricated PDMS based scaffolds but also confirm the presence of several other essential attributes such as high interconnectivity, optimum porosity, excellent mechanical strength, gaseous permeability, promising cell compatibility, water absorption capability and desired surface wettability. Therefore, scaffolds facilitate a high degree of cellular adhesion while providing a microenvironment necessary for optimal cellular infiltration and viability. Thus, the outcomes suggest that PDMS based macroporous scaffold can be used as a potential candidate for skin dressing material. In addition, the fabricated PDMS scaffolds may also be exploited for a plethora of other applications in tissue engineering and drug delivery.