Correction: Firoozi et al. A Cell-Free SDKP-Conjugated Self-Assembling Peptide Hydrogel Sufficient for Improvement of Myocardial Infarction. 2020, , 205.

The authors wish to make the following corrections to this paper [...

A self-gelling hydrogel based on thiolated hyaluronic acid for three-dimensional culture of ovine preantral follicles.

Three-dimensional (3D) ovarian follicle culture offers a promising option for fertility preservation in patients who cannot receive ovarian tissue transplantation. Our research evaluated the potential of a hydrogel composed of thiolated hyaluronic acid (HA-SH) for ovine preantral follicle development compared to routinely used alginate hydrogel (ALG). Synthesized via a carbodiimide reaction, HA-SH facilitated a self-crosslinking hydrogel through disulfide bond formation.

Earlier Detection of Alzheimer's Disease Based on a Novel Biomarker P-tau by a Label-Free Electrochemical Immunosensor.

Early detection of phosphorylated tau ( P-tau) may help as an effective treatment to control the progression of Alzheimer's disease (AD). Recently, we introduced for the first time a monoclonal antibody (mAb) with high affinity against P-tau. In this study, the P-tau mAb was utilized to develop a label-free immunosensor.

Chemical modification of hyaluronic acid improves its supportive action on embryo implantation.

Hyaluronic acid (HA) is a supplement of the embryo transfer medium that improves embryo implantation. We have suggested that the supportive action of HA can be promoted by introducing additional artificial binding sites on the HA structure. HA was modified at carboxyl sites separately with thiol (SH) and N-hydroxysuccinimide (NHS), as mucoadhesive and amine-reactive groups, respectively.

Tissue-Specific Microparticles Improve Organoid Microenvironment for Efficient Maturation of Pluripotent Stem-Cell-Derived Hepatocytes.

Liver organoids (LOs) are receiving considerable attention for their potential use in drug screening, disease modeling, and transplantable constructs. Hepatocytes, as the key component of LOs, are isolated from the liver or differentiated from pluripotent stem cells (PSCs). PSC-derived hepatocytes are preferable because of their availability and scalability.

Hydrogel-mediated delivery of microRNA-92a inhibitor polyplex nanoparticles induces localized angiogenesis.

Localized stimulation of angiogenesis is an attractive strategy to improve the repair of ischemic or injured tissues. Several microRNAs (miRNAs) such as miRNA-92a (miR-92a) have been reported to negatively regulate angiogenesis in ischemic disease. To exploit the clinical potential of miR-92a inhibitors, safe and efficient delivery needs to be established.

Dual functional construct containing kartogenin releasing microtissues and curcumin for cartilage regeneration.

Background: Regeneration of articular cartilage poses a tremendous challenge due to its limited self-repair capability and inflammation at the damaged site. To generate the desired structures that mimic the structure of native tissue, microtissues with repeated functional units such as cell aggregates have been developed. Multicellular aggregates of mesenchymal stem cells (MSCs) can be used as microscale building blocks of cartilage due to their potential for cell-cell contact, cell proliferation, and differentiation.

Generation of Scalable Hepatic Micro-Tissues as a Platform for Toxicological Studies.

Background: Currently, there is an urgent need for scalable and reliable in vitro models to assess the effects of therapeutic entities on the human liver. Hepatoma cell lines, including Huh-7, show weakly resemblance to human hepatocytes, limiting their significance in toxicity studies. Co-culture of hepatic cells with non-parenchymal cells, and the presence of extracellular matrix have been shown to influence the biological behavior of hepatocytes.

Mesenchymal stem cell-derived extracellular vesicles alone or in conjunction with a SDKP-conjugated self-assembling peptide improve a rat model of myocardial infarction.

Purpose: The aim of this study was to investigate the cardiac repair effect of human bone marrow mesenchymal stromal cells-derived extracellular vesicles (MSC-EVs) after intramyocardial injection in free form or encapsulated within a self-assembling peptide hydrogel modified with SDKP motif, in a rat model of myocardial infarction (MI).

Methods: MSC-EVs were isolated by ultracentrifuge and characterized for physical parameters and surface proteins. Furthermore, cellular uptake and cardioprotective effects of MSC-EVs were evaluated in vitro using neonatal mouse cardiomyocytes (NMCMs).

A Cell-Free SDKP-Conjugated Self-Assembling Peptide Hydrogel Sufficient for Improvement of Myocardial Infarction.

Biomaterials in conjunction with stem cell therapy have recently attracted attention as a new therapeutic approach for myocardial infarction (MI), with the aim to solve the delivery challenges that exist with transplanted cells. Self-assembling peptide (SAP) hydrogels comprise a promising class of synthetic biomaterials with cardiac-compatible properties such as mild gelation, injectability, rehealing ability, and potential for sequence modification. Herein, we developed an SAP hydrogel composed of a self-assembling gel-forming core sequence (RADA) modified with SDKP motif with pro-angiogenic and anti-fibrotic activity to be used as a cardioprotective scaffold.

Scalable and cost-effective generation of osteogenic micro-tissues through the incorporation of inorganic microparticles within mesenchymal stem cell spheroids.

Mesenchymal stem cells (MSCs) are considered primary candidates for treating complex bone defects in cell-based therapy and tissue engineering. Compared with monolayer cultures, spheroid cultures of MSCs (mesenspheres) are favorable due to their increased potential for differentiation, extracellular matrix (ECM) synthesis, paracrine activity, and in vivo engraftment. Here, we present a strategy for the incorporation of microparticles for the fabrication of osteogenic micro-tissues from mesenspheres in a cost-effective and scalable manner.

Hydrogel-Mediated Sustained Systemic Delivery of Mesenchymal Stem Cell-Derived Extracellular Vesicles Improves Hepatic Regeneration in Chronic Liver Failure.

Extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have been widely reported as promising cell-free products that show therapeutic effects of the parental cells but not their limitations. Due to the intrinsic liver tropism of MSC-EVs, they have been widely used as therapeutics or drug carriers for treatment of liver diseases. However, rapid clearance from the target site may attenuate the efficiency of systemically administered MSC-EVs.

Cannabidiol-loaded microspheres incorporated into osteoconductive scaffold enhance mesenchymal stem cell recruitment and regeneration of critical-sized bone defects.

Recruitment of mesenchymal stem cells (MSCs) to an injury site and their differentiation into the desired cell lineage are implicated in deficient bone regeneration. To date, there is no ideal structure that provides these conditions for bone regeneration. In the current study, we aim to develop a novel scaffold that induces MSC migration towards the defect site, followed by their differentiation into an osteogenic lineage.

Fabrication of microporous inorganic microneedles by centrifugal casting method for transdermal extraction and delivery.

Microneedle patches have been widely used as transdermal transport systems because of their painless and easy application. Marked rigidity, strength, biocompatibility, and physiological stability are unique features of microneedles fabricated from ceramic materials to be used as microneedle patches. However, the conventional ceramic microneedles are typically dense structures with limited free space for biomolecule loading.

Tolerance induction by surface immobilization of Jagged-1 for immunoprotection of pancreatic islets.

Although transplantation of pancreatic islets is a promising approach for treatment of type 1 diabetes mellitus, the engraftment efficiency of these islets is limited by host immune responses. Extensive efforts have been made to immunoisolate these islets by introducing barriers on the islet surface. To date, these barriers have not successfully protected islets from attack by the immune system.

Engineering mesenchymal stem cell spheroids by incorporation of mechanoregulator microparticles.

Mechanical forces throughout human mesenchymal stem cell (hMSC) spheroids (mesenspheres) play a predominant role in determining cellular functions of cell growth, proliferation, and differentiation through mechanotransductional mechanisms. Here, we introduce microparticle (MP) incorporation as a mechanical intervention method to alter tensional homeostasis of the mesensphere and explore MSC differentiation in response to MP stiffness. The microparticulate mechanoregulators with different elastic modulus (34 kPa, 0.

In situ formation of interpenetrating polymer network using sequential thermal and click crosslinking for enhanced retention of transplanted cells.

Injectable hydrogels, which are used as scaffolds in cell therapy, provide a minimally invasive strategy to enhance cell retention and survival at injection site. However, till now, slow in situ gelation, undesired mechanical properties, and weak cell adhesion characteristics of reported hydrogels, have led to improper results. Here, we developed an injectable fully-interpenetrated polymer network (f-IPN) by integration of Diels-Alder (DA) crosslinked network and thermosensitive injectable hydrogel.

In Situ Forming, Cytocompatible, and Self-Recoverable Tough Hydrogels Based on Dual Ionic and Click Cross-Linked Alginate.

A dual cross-linking strategy was developed to answer the urgent need for fatigue-resistant, cytocompatible, and in situ forming tough hydrogels. Clickable, yet calcium-binding derivatives of alginate were synthesized by partial substitution of its carboxyl functionalities with furan, which could come into Diels-Alder click reaction with maleimide end groups of a four arm poly(ethylene glycol) cross-linker. Tuning the cooperative viscoelastic action of transient ionic and permanent click cross-links within the single network of alginate provided a soft tough hydrogel with a set of interesting features: (i) immediate self-recovery under cyclic loading, (ii) highly efficient and autonomous self-healing upon fracture, (iii) in situ forming ability for molding and minimally invasive injection, (iv) capability for viable cell encapsulation, and (v) reactivity for on-demand biomolecule conjugation.

Efficient and cost-effective generation of hepatocyte-like cells through microparticle-mediated delivery of growth factors in a 3D culture of human pluripotent stem cells.

Biomedical application of human pluripotent stem cell-derived hepatocyte-like cells (hPSC-HLCs) relies on efficient large-scale differentiation, which is commonly performed by a suspension culture of three-dimensional (3D) multicellular spheroids in bioreactors. However, this approach requires large amounts of growth factors (GFs) and the need to overcome limited diffusional transport posed by the inherent 3D structure of hPSC spheroids. Here, we have hypothesized that localized delivery of GFs by incorporation of GF-laden degradable polymeric microparticles (MPs) within the hPSC spheroids would circumvent such limitations.

Facile synthesis of biphasic calcium phosphate microspheres with engineered surface topography for controlled delivery of drugs and proteins.

Biphasic calcium phosphate (BCP) microspheres are of great interest due to their high stability and osteoinductive properties at specific compositions. However, the need for optimal performance at a unique composition limits their flexibility for tuning drug release by modulation of bulk properties and presents the question of engineering surface topography as an alternative. It is necessary to have a facile method to control surface topography at a defined bulk composition.

Microparticle-Mediated Delivery of BMP4 for Generation of Meiosis-Competent Germ Cells from Embryonic Stem Cells.

Producing meiosis-competent germ cells (GCs) from embryonic stem cells (ESCs) is essential for developing advanced therapies for infertility. Here, a novel approach is presented for generation of GCs from ESCs. In this regard, microparticles (MPs) have been developed from alginate sulfate loaded with bone morphogenetic protein 4 (BMP4).

Substrate-mediated commitment of human embryonic stem cells for hepatic differentiation.

Human embryonic stem cell (hESC)-derived endodermal cells are of interest for the development of cellular therapies to treat disorders such as liver failure. The soluble form of activin A (Act) has been widely used as an in vitro inducer of definitive endoderm (DE). In this study, we have developed a nanofibrous poly (ɛ-caprolactone) substrate, biofunctionalized with Act, for directed differentiation of hESCs into DE.

Possibilities in Germ Cell Research: An Engineering Insight.

Germ cells (GCs) are responsible for fertility and disruptions in their development or function cause infertility. However, current knowledge about the diverse mechanisms involved in GC development and function is still in its infancy. This is mainly because there are low numbers of GCs, especially during embryonic development.