Hydrogel and neural progenitor cell delivery supports organotypic fetal spinal cord development in an ex vivo model of prenatal spina bifida repair

Surgical Management of Myelomeningocele

Myelomeningocele (MMC) is one of the most common abnormalities of the central nervous system that causes significant neurological impairment. Traditionally, treatment consisted of postnatal closure with the management of the complications, such as ventricular shunting. MMC is a plausible candidate for in-utero surgery because of the mechanism of neurologic damage that begins with abnormal neurulation and continues throughout gestation. Researchers discussed the benefits of in-utero closure prior to the publication of the prospective randomized multicenter Management of Myelomeningocele Study (MOMS trial). Compared to postnatal repair with maternal complications and prematurity as trade-offs, prenatal repair reduced shunting, reversed hindbrain herniation, and improved neurological function. This article discusses the diagnosis, evaluation, long-term follow-up, surgical options, and innovative treatment for fetal myelomeningocele.

Human Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Neural Differentiation of Neural Progenitor Cells

Mesenchymal stem cells (MSCs) have been adopted in various preclinical and clinical studies because of their multipotency and low immunogenicity. However, numerous obstacles relating to safety issues remain. Therefore, MSC-derived extracellular vesicles (EVs) have been recently employed. EVs are nano-sized endoplasmic reticulum particles generated and released in cells that have similar biological functions to their origin cells. EVs act as cargo for bioactive molecules such as proteins and genetic materials and facilitate tissue regeneration. EVs obtained from adipose-derived MSC (ADMSC) also have neuroprotective and neurogenesis effects. On the basis of the versatile effects of EVs, we aimed to enhance the neural differentiation ability of ADMSC-derived EVs by elucidating the neurogenic-differentiation process. ADMSC-derived EVs isolated from neurogenesis conditioned media (differentiated EVs, dEVs) increased neurogenic ability by altering innate microRNA expression and cytokine composition. Consequently, dEVs promoted neuronal differentiation of neural progenitor cells in vitro, suggesting that dEVs are a prospective candidate for EV-based neurological disorder regeneration therapy.

Dural substitutes for spina bifida repair: past, present, and future

PURPOSE

The use of materials to facilitate dural closure during spina bifida (SB) repair has been a highly studied aspect of the surgical procedure. The overall objective of this review is to present key findings pertaining to the success of the materials used in clinical and pre-clinical studies. Additionally, this review aims to aid fetal surgeons as they prepare for open or fetoscopic prenatal SB repairs.

METHODS

Relevant publications centered on dural substitutes used during SB repair were identified. Important information from each article was extracted including year of publication, material class and sub-class, animal model used in pre-clinical studies, whether the repair was conducted pre-or postnatally, the bioactive agent delivered, and key findings from the study.

RESULTS

Out of 1,121 publications, 71 were selected for full review. We identified the investigation of 33 different patches where 20 and 63 publications studied synthetic and natural materials, respectively. From this library, 43.6% focused on clinical results, 36.6% focused on pre-clinical results, and 19.8% focused on tissue engineering approaches. Overall, the use of patches, irrespective of material, have shown to successfully protect the spinal cord and most have shown promising survival and neurological outcomes.

CONCLUSION

While most have shown significant promise as a therapeutic strategy in both clinical and pre-clinical studies, none of the patches developed so far are deemed perfect for SB repair. Therefore, there is an opportunity to develop new materials and strategies that aim to overcome these challenges and further improve the outcomes of SB patients.

Multifunctional GelMA platforms with nanomaterials for advanced tissue therapeutics

Polymeric hydrogels are fascinating platforms as 3D scaffolds for tissue repair and delivery systems of therapeutic molecules and cells. Among others, methacrylated gelatin (GelMA) has become a representative hydrogel formulation, finding various biomedical applications. Recent efforts on GelMA-based hydrogels have been devoted to combining them with bioactive and functional nanomaterials, aiming to provide enhanced physicochemical and biological properties to GelMA. The benefits of this approach are multiple: i) reinforcing mechanical properties, ii) modulating viscoelastic property to allow 3D printability of bio-inks, iii) rendering electrical/magnetic property to produce electro-/magneto-active hydrogels for the repair of specific tissues (e.g., muscle, nerve), iv) providing stimuli-responsiveness to actively deliver therapeutic molecules, and v) endowing therapeutic capacity in tissue repair process (e.g., antioxidant effects). The nanomaterial-combined GelMA systems have shown significantly enhanced and extraordinary behaviors in various tissues (bone, skin, cardiac, and nerve) that are rarely observable with GelMA. Here we systematically review these recent efforts in nanomaterials-combined GelMA hydrogels that are considered as next-generation multifunctional platforms for tissue therapeutics. The approaches used in GelMA can also apply to other existing polymeric hydrogel systems.

Amniotic fluid-derived stem cell potential for therapeutic and surgical use: A review of the literature

OBJECTIVE

Spina bifida is a debilitating neutral tube defect affecting many infants. The impact and severity of spina bifida depends on whether the patient exhibits a closed defect, spina bifida occulta, or an open defect, spina bifida aperta. Patients with spina bifida have physical and mental disabilities which merit further research into less invasive, more successful treatments. In addition to serving as protection for the growing fetus and facilitating nutrient exchange, amniotic fluid (AF) is a rich source of a mixed population of stem cells. As such, in vitro culture of AF-derived stem cells has shown promise among therapeutic and surgical applications. We present a critical evaluation of the current preclinical efforts, amniotic fluid-derived stem cell (AFSC) culture process, and the subsequent therapeutic application, with a focus on improvements for spina bifida outcomes in the pediatric patient population.

METHOD

An evidence - based literature review to investigate the current literature surrounding AFSC culture and use, with an emphasis on the benefits for spina bifida treatment.

RESULTS

47 literature sources from PubMed and three studies from ClinicalTrials.gov.

CONCLUSION

This review synthesizes the current literature, which shows promising data on AFSC pluripotency, as well as successful in utero coverage from AFSC - supported environments in a multitude of animal models.