Study design
This phase I/II, randomized, controlled clinical trial was designed to evaluate the safety and efficacy of intranasal delivery of NSCs loaded by degradable patches. According to the principle of continuous enrollment, we randomly assigned all 25 patients who met the enrollment conditions from January 2018 to March 2019, including 15 patients in the treatment group (receiving NSCs transplantation three times and rehabilitation therapy; Patients 1-15) and 10 patients in the control group (receiving rehabilitation therapy only; Patients 16-25). This study was registered with ClinicalTrials.gov (NCT03005249) and the Medical Research Registration Information System (CMR-20161129–1003). And it was approved by the Ethics Committee of the Stem Cell Clinical Research Institute of the First Affiliated Hospital of Dalian Medical University (LCKY2016-60).
Eligibility and screening
Eligible participants, aged between 3 and 12 years, were clinically presenting with moderate to severe paralysis characterized by spastic CP induced by ischemic hypoxia. The Gross Motor Function Classification System (GMFCS) levels were II-V (Patient recruitment conditions are shown in Supplementary 1). All the subjects had participated in regular rehabilitation training for no less than one year but had no apparent improvements in clinical symptoms 3-6 months before treatment. All the participants’ guardians signed informed consent before participating in the study.
The NSCs nasal patch complex preparation
The allogeneic NSCs were isolated from aborted human fetal forebrain tissue. These tissues were collected from healthy pregnant women who had requested an artificial abortion. All the donors voluntarily signed informed consent forms, and the tests for human immunodeficiency virus, syphilis, hepatitis B, and other pathogenic microorganisms were negative. All donor tissue was stored in sealed containers of sterile 0.9% normal saline (NS) and transported to the stem cell preparation center registered with the China Food and Drug Administration (CFDA) via a cold chain within 6 hours of abortion. The whole procedure was in accordance with the current international Good Manufacturing Practices process for separation, extraction, amplification, passage, and detection. The NSCs were passaged every 7 to 10 days and carried out using between passages 4 to 8 for our clinical research. Before clinical application, cytopathic tests were performed for endotoxins, mycoplasma, chlamydia, and viruses. And the proportions of positive antigens expression were calculated by Flow Cytometry assay of NSCs biomarkers (Vimentin, Nestin, Notch-1, SOX2, SSEA1and Musashi-1). Immunofluorescence staining was used to detect the differentiation ability of NSCs into neurons, astrocytes, and oligodendrocytes. Observation of interaction between patches and NSCs was performed by overlaying images of cells and materials, and analyzed by confocal photographing. 2×106 cells/mL of NSCs were seeded at the materials and cultured in a 37°C incubator with 5% CO2 atmosphere for 21 days to test the degradation of patch materials in vitro by measuring the dry weight of cells and patch complexes. The 100%, 50%, 25%, and 0% extract of patch materials were used to culture NSCs for 14 days to test the biocompatibility of NSCs and materials and CCK-8 tests were used to detect the cytotoxicity of patch materials.
The NSCs nasal patch complex transplantation
Patients in the treatment group took oral Loratadine tablets (5 mg) and received intravenous Dexamethasone (4 mg) 2 hours before transplantation. And then, they were sedated with 10% Chloral Hydrate enema (50mg/kg). NSCs (5×105/kg) loaded with patches were placed on the olfactory fissure in bilateral nasal cavities by an otolaryngologist within 5 minutes. After that, patients were required to lay supine and monitored for at least 4 hours. Every child received NSCs transplantation three times with an interval of 1 month.
Safety assessments
The short-term safety profile was tested for one week after NSCs transplantation, including AEs, physical examinations, daily vital signs, dietary sleep records, physical examination records of pediatric neurologists, rehabilitation practitioners (blind method), blood biochemical examinations, ultrasonic cardiography, radiographic images of the chest and articulation/coxae, electrocardiogram, EEG, and MRI. And the long-term safety profile was monitored up to 24 months after NSCs infusion.
Scales analysis
The clinical symptoms analysis includes the gross motor, fine motor, sleep quality, social ability, speech, life adaptability, and self-care ability. The scales used for measurements include the Gross Motor Function Measure-88 (GMFM-88), the Activities of Daily Living (ADL) scale, the Sleep Disturbance Scale for Children (SDSC), and some adapted scales derived from the Gesell Growth Scale and the Chinese Psychological Development Scale, like the Fine Motor Function Scale (FMFS), the Sociability Scale (SS), the Life Adaptability Scale (LAS), and the Expressive Ability Scale (EAS). All scales were evaluated by neurologists and pediatricians blinded to the whole study. And the data were collected at baseline (1week before the treatment), 1 month (1M), 3 months (3M), 6 months (6M), and 24 months (24M) after NSCs treatment for all the CP patients.
EEG acquisition and preprocessing
The sleep EEG data were collected by a Micromed Brain SPY Plus (Micromed, Italy) at baseline, 6M, and 24M after NSCs treatment for all the CP patients. EEG signals were recorded at a 128Hz sampling rate according to the international 10-20 placement system at the following positions: C3, C4, P3, P4, O1, O2, P7, and P8. The reference electrode was located at Cz, and the ground electrode was located at central forehead. Electrode impedance was kept below 10 kΩ. Electrocardiogram data were recorded in a separate channel. 10 segments of EEG data in the non-rapid eye movement phase (NREM) II stage of sleep were randomly intercepted by an experienced technician, and each segment lasted 15 seconds. EEG signal was high pass-filtered at 0.30 Hz, low pass-filtered at 30 Hz.
Functional brain network construction
FBN refers to a graph that includes the nodes and functional connections formed by the cooperation and coordination of neural activities between neurons and between parts of the nervous system. The most commonly used method to construct FBN is the Pearson correlation coefficient (PCC) (the EEG data processing flow is shown in Supplementary 2). The Degree, Clustering coefficient, Characteristic path length, Global efficiency, and Brain network energy analysis were performed to compare the difference to baseline and control group (See Supplementary 3 for the analysis methods).
MRI acquisition
Data were acquired from each subject with a 3.0T GE Signa HDxt scanner, including T1-weighted imaging and T2-weighted imaging. Three-dimensional high-resolution T1 weighted images were scanned by brain volume scanning sequence (BRAVO) with the following parameters: TR=8.2ms, TE=3.2ms, TI=450ms, FA=12°, FOV=256mm×256mm, acquisition matrix=256×256, layer thickness=1mm, and the number of layers=188. Patients with cognitive impairment were examined under sedation with 10% chloral hydrate.
Voxel based morphological analysis
VBM analysis was performed with FSL software, which can quantitatively calculate local gray matter voxels' size and signal intensity. Skull stripping was performed first, and then a gray matter template was created at a resolution of 2×2×2 mm3 in standard space. And then, transform each voxel’s gray matter density values into gray matter volume values, followed by nonlinear registration. Use Gaussian smoothing kernel and image to discrete convolution operation, and perform the spatial smoothing of gray matter volume map after registration transformation (the result of 8 mm smoothing kernel is selected for the following analysis in this analysis), finally, the results of different smoothing degrees are obtained, that is, the gray matter volume map of each subject.
Statistical analysis
All statistical analyses were performed with the Software Package for Social Sciences for Windows v23.0 (IBM, Armonk, New York). Categorical data are presented as frequencies and percentages. Continuous data are presented as the mean ± standard deviation (SD) or median (Q1-Q3) as appropriate. To compare categorical data between groups, χ2 tests were performed. Continuous data were compared using the independent Student’s t-test or Mann-Whitney U test, as appropriate. Changes of variables at 24 months relative to baseline in study and control group were compared using paired Student’s t-test or Wilcoxon rank-sum test. Changes of variables at baseline, 1M, 3M, 6M and 24M in study group were compared using the one-way repeated-measures ANOVA or generalized linear mixed model. A two-tailed P value <0.05 was considered statistically significant.