Glycerol Sebacate Research Articles

Combination of polyglycerol sebacate coated with collagen for vascular engineering

Introduction: Here, we monitored the cytocompatibility of scaffolds consisting of poly (glycerol sebacate) (PGS) coated with collagen (Col) for endothelial cell activity after 72 hours. Methods: Human endothelial cells were allocated into Control, PGS, and PGS+Col groups. Scaffolds were characterized using FTIR and HNMR spectroscopy. Contact angel analysis and SEM were used to study wettability, surface morphology, and cell attachment. Cell survival was assessed using LDH leakage assay. Levels of Tie-1, Tie-2, VE-Cadherin, and VEGFR-2 were measured using western blotting and real-time PCR. Results: FTIR and HNMR analyses revealed the proper blending in PGS+Col group. SEM imaging exhibited a flat surface in the PGS group while thin Col fibers were detected in PGS+Col surface. The addition of Col to the PGS reduced the contract angle values from 97.3˚ to 81.1˚. Compared to PGS substrate alone, in PGS+Col group, cells appropriately attached to the surface. PGS and PGS+Col did not alter the leakage of LDH to the supernatant compared to control cells, showing the cytocopatiblity of PGS-based scaffolds. SOD and NO levels were increased significantly in PGS (p<0.05) and PGS+Col groups (p<0.001), respectively. We found that PGS+Col decreased Tie-1 content in endothelial cells whereas protein levels of Tie-2 and VE-Cadherin and expression of VEGFR-2 remained unchanged compared to PGS and control groups. Conclusion: Simultaneous application of Col and PGS can stimulate normal endothleial cell morphology without the alteration of tyrosine kinases receptors and cadherin.

The Effect of Vitamin C-Loaded Electrospun Polycaprolactone/Poly (Glycerol Sebacate) Fibers for Peripheral Nerve Tissue Engineering

Vitamin C (VC) is an essential supplement that plays a vital role in cellular processes and functions and has been applied for therapeutic purposes for many years. The beneficial effects of VC on peripheral nerve regeneration have been gained lots of attention. In this study, electrospun polycaprolactone (PCL)/polyglycerol sebacate (PGS) fibers incorporated with different concentrations of VC (5, 10, and 15 wt.%) were developed for peripheral nerve tissue engineering. The morphology of the fibers was investigated using scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), tensile analysis (Young’s modulus, ultimate tensile strength (UTS), and elongation at break), release profile of VC from the PCL/PGS fibers, in vitro degradation, water uptake behavior, and contact angle measurements were also studied. MTT assay and SEM were utilized to evaluate the attachment and viability of pheochromocytoma cells (PC12) on the scaffolds. The results showed that all scaffolds had a uniform diameter and mean diameter deceased from 1.24 to 0.88 µm followed by increasing VC. Young’s modulus and UTS enhanced with increasing in VC percentage. MTT assay demonstrated that PCL/PGS containing 5 wt.% VC had a greater viability rate among other scaffolds. Our outcome indicated possible applicability of VC containing scaffolds for nerve tissue engineering.

Fabrication of novel PCL/PGS fibrous scaffold containing HA and GO through simultaneous electrospinning-electrospray technique

Herein, poly(caprolactone)/poly (glycerol sebacate) (PCL/PGS) fibrous structures incorporating hydroxyapatite (HA) and graphene oxide (GO) nanofillers were prepared through two procedures, including electrospinning and simultaneous electrospinning/electrospray procedures. Accordingly, introducing nanofillers into the structures through the simultaneous method led to improving the mechanical strength from 3.69 to 4.95 MPa. The electrospray nanofillers caused improvement of the amorphous regions (up to 83.4%) and increased the degradation rate. Furthermore, the filler-filled electrospun/electrospray sample illustrated the highest cell viability of 94.81 ± 0.5%. The results implied that the simultaneous procedure is promising for fabricating filler-loaded membranes as bone tissue scaffolds.

Polyglycerol sebacate (PGS)-based composite and nanocomposites: properties and applications

Nowadays, elastomeric materials with a wide range of properties as a valuable strategy play a wide role in meeting the needs of reconstructive medicine and tissue engineering. In the last two decades, poly glycerol sebacate has shown great potential in the medical industry, especially in the engineering of soft tissues. Although PGS has an elastomeric and biocompatibility nature, it has poor mechanical properties. To overcome this problem, different composites and nanocomposites with hydroxyapatite, carbon nanotubes, graphene, etc. can be used. In this study, we review the properties of PGS-based composite and nanocomposites, as well as their applications in tissue engineering.

Preparation and characterization of a new sustainable bio-based elastomer nanocomposites containing poly(glycerol sebacate citrate)/chitosan/n-hydroxyapatite for promising tissue engineering applications

Poly (glycerol sebacate citrate) (PGSC) has potential applications in tissue engineering due to its biodegradability and suitable elasticity. However, its applications are restricted owing to its acidity and high degradation rate. In this study, a new bio-nanocomposite based on PGSC has been synthesized by incorporating chitosan (CS) and various concentrations of hydroxyapatite nanoparticles (n-HA). It is assumed that the basicity of a CS and hydroxyl groups of n-HA will reduce the acidity of PGSC and control the rate of degradation. Also, the biocompatibility of n-HA and inherent hydrophilicity of CS can improve cell adhesion and proliferation of PGSC-based scaffolds. FTIR, XRD, FESEM, and EDX tests confirmed the synthesis of these nanocomposites and the interaction between each of the components. The results of the DMTA test also indicated the elastic behavior of the samples embedded with n-HA. The hydrophilicity assay demonstrated that the water contact angle of the scaffolds decreased as the concentration of n-HA augmented, and it reached the value of 44 ± 0.9° for nanocomposite containing 5 wt.% n-HA. The degradation rate of all PGSC nanocomposites was reduced due to the anionic groups of n-HA and CS. TGA assay indicated that the incorporation of n-HA led to the enhancement of scaffolds’ thermal stability. Furthermore, the synergistic effect of CS and n-HA on the enhancement of protein adsorption and cell proliferation was confirmed through protein adhesion and MTT assay, respectively. Consequently, the addition of n-HA and CS perform the new bio-nanocomposites scaffolds based on PGSC with sufficient hydrophilicity, flexibility, and thermal stability in tissue engineering applications.

Incorporation of Glutamic Acid or Amino-Protected Glutamic Acid into Poly(Glycerol Sebacate): Synthesis and Characterization.

Poly(glycerol sebacate) (PGS), a soft, tough elastomer with excellent biocompatibility, has been exploited successfully in many tissue engineering applications. Although tunable to some extent, the rapid in vivo degradation kinetics of PGS is not compatible with the healing rate of some tissues. The incorporation of L-glutamic acid into a PGS network with an aim to retard the degradation rate of PGS through the formation of peptide bonds was conducted in this study. A series of poly(glycerol sebacate glutamate) (PGSE) containing various molar ratios of sebacic acid/L-glutamic acid were synthesized. Two kinds of amino-protected glutamic acids, Boc-L-glutamic acid and Z-L-glutamic acid were used to prepare controls that consist of no peptide bonds, denoted as PGSE-B and PGSE-Z, respectively. The prepolymers were characterized using 1H-NMR spectroscopy. Cured elastomers were characterized using FT-IR, DSC, TGA, mechanical testing, and contact angle measurement. In vitro enzymatic degradation of PGSE over a period of 28 days was investigated. FT-IR spectroscopy confirmed the formation of peptide bonds. The glass transition temperature for the elastomer was found to increase as the ratio of sebacic acid/glutamic acid was increased to four. The decomposition temperature of the elastomer decreased as the amount of glutamic acid was increased. PGSE exhibited less stiffness and larger elongation at break as the ratio of sebacic acid/glutamic acid was decreased. Notably, PGSE-Z was stiffer and had smaller elongation at break than PGSE and PGSE-B at the same molar ratio of monomers. The results of in vitro enzymatic degradation demonstrated that PGSE has a lower degradation rate than does PGS, whereas PGSE-B and PGSE-Z degrade at a greater rate than does PGS. SEM images suggest that the degradation of these crosslinked elastomers is due to surface erosion. The cytocompatibility of PGSE was considered acceptable although slightly lower than that of PGS. The altered mechanical properties and retarded degradation kinetics for PGSE reflect the influence of peptide bonds formed by the introduction of L-glutamic acid. PGSE displaying a lower degradation rate compared to that for PGS can be used as a scaffold material for the repair or regeneration of tissues that are featured by a low healing rate.

Introducing a new approach to preparing bionanocomposite sponges based on poly(glycerol sebacate urethane) (PGSU) with great interconnectivity and high hydrophilicity properties for application in tissue engineering

In this study, a three-dimensional porous structure of poly(glycerol sebacate urethane) (PGSU) comprising nano-clay and polyacrylic acid (PAAc) was synthesized through a two-step synthesis route. Particulate leaching technique by introducing spun sugar as porogen was also performed as a fabrication method. It was hypothesized that the introduction of spun sugar with its filamentous shape would create interrelated pores required for cell adhesion and proliferation. Polarity, stiffness, and swelling capacity of PGSU would be enhanced by eco-friendly in-situ polymerization of PAAc and the contribution of biocompatible nanoclay. After characterizing the synthesis of PGSU-based scaffolds, viscoelastic behavior, hydrophilicity, and biocompatibility of scaffolds were evaluated. Doubling of swelling capacity in dry state and decrement of water contact angle (WCA) approved the effect of polar carboxyl groups of PAAc in the improvement of polarity and hydrophilicity of PGSU. DMTA results in dry and wet states demonstrated that increasing the concentration of nanoclay and the presence of PAAc chains led to the increase in the storage modulus while the elastic behavior at body temperature was preserved. Eventually, the feasibility of the porous structure of PGSU-based scaffolds in tissue engineering became clear by in vitro biocompatibility test and significant cell adhesion in plasma-treated PGSU/PAAC/nanoclay. Accordingly, introducing clay nanoparticles and in-situ polymerization of acrylic acid, together with porous structure, make PGSU a suitable substrate for cellular interactions.

Revealing Localised Mechanochemistry of Biomaterials Using In Situ Multiscale Chemical Analysis.

The study of mechanical and chemical phenomena arising within a material that is being subjected to external stress is termed mechanochemistry (MC). Recent advances in MC have revealed the prospect not only to enable a greener route to chemical transformations but also to offer previously unobtainable opportunities in the production and screening of biomaterials. To date, the field of MC has been constrained by the inability of current characterisation techniques to provide essential localised multiscale chemically mapping information. A potential method to overcome this is secondary electron hyperspectral imaging (SEHI). SEHI is a multiscale material characterisation technique applied within a scanning electron microscope (SEM). Based on the collection of secondary electron (SE) emission spectra at low primary beam energies, SEHI is applicable to the chemical assessment of uncoated polymer surfaces. Here, we demonstrate that SEHI can provide in situ MC information using poly(glycerol sebacate)-methacrylate (PGS-M) as an example biomaterial of interest. This study brings the use of a bespoke in situ SEM holder together with the application of SEHI to provide, for the first time, enhanced biomaterial mechanochemical characterisation.

An electrospun PGS/PU fibrous scaffold to support and promote endothelial differentiation of mesenchymal stem cells under dynamic culture condition

Shear stress is one of the dominant mechanical stimuli present in a vessel wall and an important regulator of endothelial cells functions. It has been shown that shear stress can derive endothelial differentiation of mesenchymal stem cells (MSCs). Engineering a vascular basement membrane thus requires a scaffold that is not only biocompatible but also able to withstand shear stress and support endothelial differentiation of MSCs in the presence of shear stress. In this study, we fabricated an electrospun poly(glycerol sebacate) (PGS)/polyurethane (PU) fibrous scaffold and characterized its physical properties, mechanical properties, and platelet adhesion and hemolysis induction. The developed PGS/PU indicated desirable hydrophilicity (∼41°), an elastic modulus (∼27 MPa) close to that of the Saphenous vein, and no significant level of hemolysis (∼0.03%) and platelet adhesion. The PGS/PU was next seeded with MSCs and implemented in a custom-made bioreactor for applying shear stress (magnitude: ∼15 dyn/cm2, duration: 24 h). Investigating the endothelial-specific gene expression in the presence of shear stress revealed that expression levels of VEGF R-2, VWF, and PCAM-1 significantly increased for the cells seeded on the PGS/PU scaffold compared to those seeded on a glass coverslip. It is thereby concluded that the developed PGS/PU fibrous scaffold can support and significantly promote the endothelial differentiation of MSCs in the presence of shear stress without the need for any growth factors. The findings of this study could provide insights into engineering a functional vascular basement membrane in vitro for vascular tissue engineering applications.

Syndecan‐4 functionalized elastomeric biomaterial promotes in situ endovascular tissue repair and regeneration

While many acellular endovascular biomaterials have been developed to attract endothelial precursors cells (EPCs) to promote tissue repair and regeneration, none of them truly create a conducive microenvironment for EPC adhesion, growth, and differentiation. Syndecan‐4 is a heparan sulfate containing proteoglycan with high affinity and binding specificity for various growth factors, cytokines, chemokines, is a significant component of the endothelial cell glycocalyx. In this study, an endovascular biomaterial composite of type I collagen, poly (glycerol sebacate) and silk fibroin, termed PFC, was functionalized with syndecan‐4 and stromal cell‐derived factor 1 alpha (SDF‐1α) to study the interaction with EPCs. The functionalized biomaterial (PFC_SYN4) significantly promoted the adhesion of EPCs. PFC_SYN4 captured 50% more cells than PFC under dynamic binding conditions (P&lt;0.001) and 20% more cells than PFC under physiological flow conditions (P&lt;0.05). Competitive binding studies showed EPCs bound to PFC_SYN4 in the presence of excess leucocytes. After 2 hours of incubation, average cell spreading area of EPCs on PFC_SYN4 (1252 ± 415 µm2) was significantly greater (P&lt;0.05) than on PFC (1149 ± 392 µm2). At day 4, vWF expression was doubled for cells on PFC and PFC_SYN4. CD31 was upregulated about 3.4 fold in cells cultured on PFC and 7.2 fold in cells cultured on PFC_SYN4 (P&lt;0.05), at day 7, CD31 and vWF expression was significantly greater than on day 4. PFC_SYN4 increased 10.6 fold for vWF and PFC increased 4 fold. PFC_SYN4 had doubled amount of CD31 expression compared to PFC (P&lt;0.05). This study expands our knowledge of the potential benefit of using syndecan‐4 to functionalize acellular biomaterials and facilitate the adhesion, growth, and differentiation of precursor cells in order to further promote tissue repair and regeneration.

3D Multiple Triangular Prisms for Highly Sensitive Non-Contact Mode Triboelectric Bending Sensors.

Here, a highly sensitive triboelectric bending sensor in non-contact mode operation, less sensitive to strain, is demonstrated by designing multiple triangular prisms at both sides of the polydimethylsiloxane film. The sensor can detect bending in a strained condition (up to 20%) as well as bending direction with quite high linear sensitivity (~0.12/degree) up to 120°, due to the electrostatic induction effect between Al and poly (glycerol sebacate) methacrylate. Further increase of the bending angle to 135° significantly increases the sensitivity to 0.16/degree, due to the contact electrification between them. The sensors are attached on the top and bottom side of the proximal interphalangeal and wrist, demonstrating a directional bending sensor with an enhanced sensitivity.

Synthesis, Characterization and Electron Beam Curing of Poly(Glycerol Sebacate Methacrylate)

Poly (glycerol sebacate) pre-polymer was synthesized and methacrylated to different degrees (PGSm-0.1, PGSm-0.2, PGSm-0.4) to impart processability using radiation technology. Spectroscopic analyses (FTIR and 1H NMR) confirmed the presence of ester linkage in the poly (glycerol sebacate) chain and the methacrylate group in the derivatives. The degree of methacrylation (DM) computed from the 1H NMR signal integration ranged from 0.1 to 0.4. The molecular weight and polydispersity increased with an increase in DM. The DSC thermograms suggested better elastomeric properties at ambient temperature, while the TGA showed no significant shift in the degradation parameters of PGS upon methacrylation. Electron beam curing of the PGSm samples was employed, and the resulting films were characterized for gel content, surface topography, and wettability. The crosslinked PGSm-0.2 and PGSm-0.4 samples exhibited high gelation at doses 5-50 kGy. However, no gelation above 15 kGy occurred in PGSm-0.1, suggesting that main chain scission reactions prevailed. The surface properties of the films obtained from the AFM and contact angle measurements revealed high surface roughness and wettability.

Preparation and properties investigation of biodegradable poly (glycerol sebacate-co-gelatin) containing nanoclay and graphene oxide for soft tissue engineering applications.

This study has attempted to systematically investigate the influence of nanoclay and graphene oxide (GO) on thermal, mechanical, hydrophobic, and, most importantly, biological properties of poly(glycerol sebacate)/gelatin (PGS/gel) nanocomposites. The PGS/gel copolymer nanocomposites were successfully synthesized via in situ polymerization, approved by rudimentary characterization methods. The nanofillers were appropriately dispersed within the elastomeric matrix according to morphological studies. Also, the fillers posed as a hydrophobic entity that slightly decreased the hydrophilic properties of PGS/gel. This could be sensed clearly in hybrid composite due to the robust network of GO and clay. Water contact angle values for gelatin-contained nanocomposites were reported in the range of 38.42° to 66.7°, indicating the hydrophilic nature of the prepared samples. Thermal and mechanical studies of nanocomposites displayed rather contradicting results as the former improved while a slight decrease in the latter was noticed compared to the pristine specimens. In dry conditions, their storage modulus was in the range of 0.94-6.4MPa, making them suitable for mimicking some soft tissues. The swelling ratio for nanocomposites containing nanoparticles was associated with an ascending trend so that GO improved the swelling rate by up to 45%. Biological analyses, such as Ames and in vitro cell viability tests, exhibited promising outcomes. As for the mutagenesis effect, the PGS and hybrid samples showed negative results. The presence of functional groups on the nanofillers' surface positively influenced the cells' metabolic activity as well as its attachment to the matrix. After 7 days, the cell proliferation rate resulted in an 82% improvement for the GO-containing nanocomposite, significantly higher than its neat counterpart (65%). This study has shown the feasibility of the prepared bio-elastomer nanocomposites for diverse tissue engineering applications.

Lipase-Catalyzed Poly(glycerol-1,8-octanediol-sebacate): Biomaterial Engineering by Combining Compositional and Crosslinking Variables.

This study examined poly(glycerol-1,8-octanediol-sebacate) (PGOS) copolymers with low-level substitution of O (1,8-octanediol) for G (glycerol) units (G/O ratios 0.5:0.5, 0.66:0.33, 0.75:0.25, 0.8:0.2, and 0.91:0.09) prepared in bulk by immobilized Candida antarctica Lipase B (N435) catalysis. The central question explored was the extent that exchanging less than half of poly(glycerol sebacate) (PGS) glycerol units with 1,8-octanediol can be used as a strategy to fine-tune biomaterial properties. Synthesized copolymers having G/O ratios of 0.66:0.33, 0.75:0.25, 0.8:0.2, and 0.91:0.09 have similar molecular weights, where Mw varied from 52,800 to 63,800 g/mol, Mn varied from 5100 to 6450 g/mol, and ĐM (molecular mass dispersity, Mw/Mn) values were also similar (8.4-11.4). All of the copolymers were branched, and dendritic glycerol units reached 11% for PGOS-0.91:0.09:1.0. Analysis of DSC second heating scans revealed that copolymers with higher 1,8-octanediol contents have relatively higher Tm and ΔHf values. Over the copolymer compositional range studied herein, Tm and ΔHf values varied from 5.3 to 21.1 °C and 8.0 to 23.1 J/g, respectively. Stress-strain curves of PGOS copolymers cured at 140 °C for 48 h exhibited either a unimodal, bimodal, or trimodal response to tensile loading. Varying G/O from 10:1 to 2:1 resulted in significant increases in the peak stress (0.26-4.01 MPa), preyield modulus (0.65-62.59 MPa), failure to strain (64-110%), and failure toughness (0.1-0.56 MPa). This demonstrates that altering the G/O ratio over a narrow compositional range provides biomaterials with widely different yet tunable mechanical properties. Further investigation of PGOS-0.75:0.25:1.0 films revealed that varying the cure conditions from 120 to 160 °C for periods of 24-72 h provides access to biomaterials with a failure strain range from 15 to 224% and Young's modulus from 1.17 to 10.85 MPa. Hence, using the dual variables of compositional variation and changes in cure conditions provides an exciting platform for PGS analogues to optimize material-tissue interactions. Increased contents of 1,8-octanediol slowed in vitro degradation. Slowed degradation of PGOS relative to PGS will be valuable for use in slower healing wounds.

Preparation and characterization of a new bio nanocomposites based poly(glycerol sebacic-urethane) containing nano-clay (Cloisite Na+ ) and its potential application for tissue engineering.

Nanocomposites containing clay nanoparticles often present favorable properties such as good mechanical and thermal properties. They frequently have been studied for tissue engineering (TE) and regenerative medicine applications. On the other hand, poly(glycerol sebacate) (PGS), a revolutionary bioelastomer, has exhibited substantial potential as a promising candidate for biomedical application. Here, we present a facile approach to synthesizing stiff, elastomeric nanocomposites from sodium-montmorillonite nano-clay (MMT) in the commercial name of Cloisite Na+ and poly(glycerol sebacate urethane) (PGSU). The strong physical interaction between the intercalated Cloisite Na+ platelets and PGSU chains resulted in desirable property combinations for TE application to follow. The addition of 5% MMT nano-clay resulted in an over two-fold increase in the tensile modulus, increased the onset thermal decomposition temperature of PGSU matrix by 18°C, and noticeably improved storage modulus of the prepared scaffolds, compared with pure PGSU. As well, Cloisite Na+ enhanced the hydrophilicity and water uptake ability of the samples and accelerated the in-vitro biodegradation rate. Finally, in-vitro cell viability assay using L929 mouse fibroblast cells indicated that incorporating Cloisite Na+ nanoparticles into the PGSU network could improve the cell attachment and proliferation, rendering the synthesized bioelastomers potentially suitable for TE and regenerative medicine applications.

Surface channel patterned and endothelialized poly(glycerol sebacate) based elastomers.

Prevascularization of tissue equivalents is critical for fulfilling the need for sufficient vascular organization for nutrient and gas transport. Hence, endothelial cell culture on biomaterials is of great importance for researchers. Numerous alternate strategies have been suggested in this sense, with cell-based methods being the most commonly employed. In this study, poly (glycerol sebacate) (PGS) elastomers with varying crosslinking ratios were synthesized and their surfaces were patterned with channels by using laser ablation technique. In order to determine an ideal material for cell culture studies, the elastomers were subsequently mechanically, chemically, and biologically characterized. Following that, human umbilical vein endothelial cells (HUVECs) were seeded into the channels established on the PGS membranes and cultured under various culture conditions to establish the optimal culture parameters. Lastly, the endothelial cell responses to the synthesized PGS elastomers were evaluated. Remarkable cell proliferation and impressive cellular organizations were noticed on the constructs created as part of the investigation. On the concrete output of this research, arrangements in various geometries can be created by laser ablation method and the effects of various molecules, drugs or agents on endothelial cells can be evaluated. The platforms produced can be employed as an intermediate biomaterial layer containing endothelial cells for vascularization of tissue-engineered structures, particularly in layer-by-layer tissue engineering approaches.

Micropatterned conductive elastomer patch based on poly (glycerol sebacate)-graphene for cardiac tissue repair

Preparing a micropatterned elastomer film with characteristics that can simulate the mechanical properties, anisotropy, and electroactivity of natural myocardial tissues is crucial in cardiac tissue engineering after myocardial infarction (MI). Therefore, in this study, we developed several elastomeric films with a surface micropattern based on poly (glycerol sebacate) (PGS) and graphene (Gr). These films have sufficient mechanical strength (0.6 ± 0.1–3.2 ± 0.08 MPa) to withstand heartbeats, and the micropatterned structure also satisfies the natural myocardium anisotropy in the transverse and vertical. Moreover, Gr makes these films conductive (up to 5.80 × 10−7 S m−1), which is necessary for the conduction of electrical signals between cardiomyocytes and the cardiac tissue. Furthermore, they have good cytocompatibility and can promote cell proliferation in H9c2 rat cardiomyocyte cell lines. In vivo test results indicate that these films have good biocompatibility. Notably, a film with 1 wt% Gr content (PGS–Gr1) significantly affects the recovery of myocardial function in rats after MI. This film effectively decreased the infarct size and degree of myocardial fibrosis and reduced collagen deposition. Echocardiographic evaluation showed that after treatment with this film, the left ventricular internal dimension (LVID) in systole and LVID in diastole of rats exhibited a significant downward trend, whereas the fractional shortening and ejection fraction were significantly increased compared with the control group. These data indicate that this electroactive micropatterned anisotropic elastomer film can be applied in cardiac tissue engineering.

3D Printing of Mechanically Resistant Poly (Glycerol Sebacate) (PGS)‐Zein Scaffolds for Potential Cardiac Tissue Engineering Applications

Due to the limited regenerative capacity of the natural human myocardium, 3D printing of the cyclic polyester poly (glycerol sebacate) (PGS) offers a promising alternative to produce scaffolds (cardiac patches) for cardiac tissue engineering. Since the 3D printability and subsequent thermal crosslinking of pure PGS without any modification or additives are challenging, a PGS‐zein‐salt‐based printing process is developed in this work by mixing PGS pre‐polymer with ground and sieved sodium chloride particles and additionally with different amounts of the corn protein zein. The resulting inks show excellent printability and high shape fidelity both during the printing process and after thermal crosslinking. Chemical analysis indicates the successful integration of zein into the PGS backbone. Mechanical characterization shows the anisotropic behavior of the structure in the alternating printing direction. Subsequent biological assessments reveal no cytotoxic effects on C2C12 cells, rendering the developed PGS‐zein combination a suitable material for 3D printing of cardiac patches.

Biodegradable functional macromolecules as promising scaffolds for cardiac tissue engineering

AbstractCardiovascular diseases, the major international health problem and the leading cause of death worldwide have been increasing in recent years due to population aging and lifestyle changes. Loss of cardiac muscle function after myocardial damage is one of the most critical challenges in cardiovascular medicine that has not yet been overcome. Tissue engineering (TE) has emerged as a promising therapeutic approach in modern medicine, targeting the substitution of damaged tissue with functional tissue grown inside an artificial scaffold. Great efforts have been made toward the construction of tissue engineering scaffolds that paved the way for extracellular matrix (ECM)‐like biomaterial. In cardiac tissue engineering, key parameters must be determined to select the ideal biomaterial, such as biocompatibility, conductivity, mechanical features, degradation and swelling rate, surface properties, and cell viability, growth and proliferation. Among different scaffolding materials, a wide range of natural biological macromolecules and synthetic macromolecules have been utilized to produce scaffolds with multifunctionality for cardiac tissue engineering (CTE). In this review, we have focused on recent achievements in the field of synthetic biodegradable macromolecules (such as aliphatic polyesters, polyurethane, poly (glycerol sebacate)) and the significant strategies to construct electrically conductive scaffolds to regenerate the function of native cardiac tissue. These biodegradable macromolecules have several attractive properties, including biocompatibility, elasticity, good mechanical properties, compatibility with native cardiac tissue, and proper surface biochemistry to increase cardiac cell adhesion, making them appropriate candidates for CTE. Recently, a growing trend in the use of conductive scaffolds for cardiac regeneration has been witnessed. Different materials ranging from metals, ceramics, and polymers have been used as parts of conductive scaffolds for CTE, possessing conductivity assortments from a range of semiconductive to conductive. Moreover, this review paper also focuses on the main strategies to create electroconductive scaffolds for in vitro cardiac muscle regeneration.

Shape memory poly (glycerol sebacate)‐based electrospun fiber scaffolds for tissue engineering applications: A review

AbstractElectrospun fiber scaffolds has made a huge progress in tissue engineering applications owing to their continuous morphology with variable chemical, physical, and biological properties. In this review paper, we reviewed the electrospinning technique, its processing parameters and characterizations involved. A focus on shape memory poly (glycerol sebacate) (PGS)‐based electrospun fiber scaffolds for tissue engineering field was explored. The stimuli responsive PGS scaffold has gained much attention due to its ability to self‐expanding, self‐deploying, or self‐fitting. Herein, the electrospinning of shape memory PGS‐based scaffolds, particularly their processing parameters, properties, and characterizations have been reviewed. Besides, other issues concerning the technology constraints, challenges, and future directions are also discussed.