Expansion of human umbilical cord derived mesenchymal stem cells in regenerative medicine

BACKGROUND

Stem cells are undifferentiated cells that possess the potential for self-renewal with the capacity to differentiate into multiple lineages. In humans, their limited numbers pose a challenge in fulfilling the necessary demands for the regeneration and repair of damaged tissues or organs. Studies suggested that mesenchymal stem cells (MSCs), necessary for repair and regeneration via transplantation, require doses ranging from 10 to 400 million cells. Furthermore, the limited expansion of MSCs restricts their therapeutic application.

AIM

To optimize a novel protocol to achieve qualitative and quantitative expansion of MSCs to reach the targeted number of cells for cellular transplantation and minimize the limitations in stem cell therapy protocols.

METHODS

Human umbilical cord (hUC) tissue derived MSCs were obtained and re-cultured. These cultured cells were subjected to the following evaluation procedures: Immunophenotyping, immunocytochemical staining, trilineage differentiation, population doubling time and number, gene expression markers for proliferation, cell cycle progression, senescence-associated β-galactosidase assay, human telomerase reverse transcriptase (hTERT) expression, mycoplasma, cytomegalovirus and endotoxin detection.

RESULTS

Analysis of pluripotent gene markers Oct4, Sox2, and Nanog in recultured hUC-MSC revealed no significant differences. The immunophenotypic markers CD90, CD73, CD105, CD44, vimentin, CD29, Stro-1, and Lin28 were positively expressed by these recultured expanded MSCs, and were found negative for CD34, CD11b, CD19, CD45, and HLA-DR. The recultured hUC-MSC population continued to expand through passage 15. Proliferative gene expression of Pax6, BMP2, and TGFb1 showed no significant variation between recultured hUC-MSC groups. Nevertheless, a significant increase (P < 0.001) in the mitotic phase of the cell cycle was observed in recultured hUC-MSCs. Cellular senescence markers (hTERT expression and β-galactosidase activity) did not show any negative effect on recultured hUC-MSCs. Additionally, quality control assessments consistently confirmed the absence of mycoplasma, cytomegalovirus, and endotoxin contamination.

CONCLUSION

This study proposes the development of a novel protocol for efficiently expanding stem cell population. This would address the growing demand for larger stem cell doses needed for cellular transplantation and will significantly improve the feasibility of stem cell based therapies.

Blunt abdominal trauma patients presenting to a tertiary care facility of Pakistan: A three years' experience

Blunt abdominal trauma (BAT) refers to injuries without wounds entering the peritoneal cavity due to road traffic accidents (RTA) and falls, as a result of collision or counter collision. The objective of the present study was to determine the frequency of patients with visceral injuries in blunt abdominal trauma. This study was carried out in the Department of Surgery, including ward-3 of Jinnah Post Graduate Medical Centre, Karachi, from November 2017 till November 2020. The study design was descriptive case series. During the study period, the data of 112 patients was collected, which comprised of 102 males and 10 females. All the patients between 12 to 65 years of age (mean age:31.84±13.14 years) presenting to the emergency with < 24 hours of abdominal trauma, were included in the study. Organs involved during blunt abdominal trauma were observed and frequency was recorded. Liver injuries were found in 48(42.28%) patients, intestinal injuries in 40(35.7%), splenic injuries in 32(28.5%), kidney injuries in 24(21.4%), pancreatic injuries in 8(7.1%) and stomach injuries in 4(3.5%) patients. Grade 4 liver injury was found in 80(71%) patients, Grade 2 and 3 splenic injuries in 56(50%) patients whereas 47(42%) patients had grade 1 kidney injury. Liver was found to be the most frequent organ involved, followed by intestine and spleen.

Visceral Injuries in Patients with Blunt and Penetrating Abdominal Trauma Presenting to a Tertiary Care Facility in Karachi, Pakistan

Introduction

Abdominal injuries are responsible for 10% of the mortalities due to trauma. Delays in early diagnosis or misdiagnoses are two major reasons for the mortality and morbidity associated with abdominal trauma. The objectives of this study were to determine the frequency of visceral injuries in patients with abdominal trauma and compare the frequency of visceral injuries in patients with blunt and penetrating abdominal trauma.

Methods

We conducted a cross-sectional study from May 2016 to May 2018 of patients presenting to the emergency department (ED) at Jinnah Postgraduate Medical Center in Karachi, Pakistan. Patients were 12 to 65 years old and presented within 24 hours of abdominal trauma. We recorded the type of abdominal visceral injuries, such as liver, spleen, intestine, stomach, mesentery, and pancreas.

Results

The mean patient age was 31 ±13 years. Penetrating trauma was found in most patients (n=72, 51%). Liver injuries were found in 37 patients (26.4%), spleen injuries in 29 patient (20.7%), stomach injuries in eight patients (5.7%), intestine injuries in 67 patients (47.9%), mesentery injuries in 21 patients (15%), and pancreas injuries in nine patients (6.4%). The type of abdominal trauma was found significantly associated with liver injury (p-value 0.021), and intestine injury (p-value <0.001).

Conclusion

Penetrating trauma (51.4%) was more common than blunt trauma (48.5%), and intestines are the most commonly affected by penetrating and blunt trauma injuries (70.1% and 47.8%, respectively). The liver is the most commonly affected (42.85%) in blunt trauma injuries, followed by the spleen (28.5%). The appropriate authorities should consider this information when instituting public health and safety initiatives.