Dual-responsive PDA-HP hydrogel enables mitochondria-targeted mild photothermal therapy for spinal cord repair methods
Aim. Evidence-backed execution summary for Dual-responsive PDA-HP hydrogel enables mitochondria-targeted mild photothermal therapy for spinal cord repair methods from Dual-responsive PDA-HP hydrogel enables mitochondria-targeted mild photothermal therapy for spinal cord repair.
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mouse
Subject model for the experiment.
- Use
- confirm full cohort details in the source paper
Design and preparation of PDA-HP hydrogel
reagent used in the protocol.
- Use
- Heparin-poloxamer (HP) conjugates were prepared via EDC/NHS-mediated coupling. Poloxamer 407 was first activated with 1.3 mM 4-nitrophenyl chloroformate, followed by reaction with ethylenediamine to produce an amine-terminated intermediate. This intermediate was subsequently reacted with heparin in MES buffer o...
In vitro cellular experiments
reagent used in the protocol.
- Use
- The ND7/23 cell line, derived from dorsal root ganglia, was obtained from the Stem Cell Bank of the Chinese Academy of Sciences and cultured in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10 % fetal bovine serum (FBS) under standard conditions.
In vitro cellular experiments
reagent used in the protocol.
- Use
- To assess T-BHP-induced cytotoxicity in ND7/23 cells, cell viability was measured using the CCK-8 assay (C0037, Beyotime, China). ND7/23 cells were seeded at 8 × 10 3 cells per well in 96-well plates and allowed to stabilize overnight. Culture medium was then replaced, and cells were e...
Photothermal treatment and hydrogel co-culture
reagent used in the protocol.
- Use
- For co-culture experiments, ND7/23 cells were seeded in 24-well plates (1 × 10 5 cells/well) and incubated with 100 µL of PDA-HP pre-gel solution per well. The mixture was maintained at 37 °C for 10 min to allow complete gelation, forming a thin hydrogel layer over...
Live-dead assay
reagent used in the protocol.
- Use
- Cell viability within the hydrogel was assessed using a Live/Dead Viability/Cytotoxicity Kit (C2015S, Beyotime, China) following the manufacturer's instructions. ND7/23 cells were co-cultured with PDA-HP hydrogel for 48 h, after which the staining solution was applied, and samples were incubated at 37...
Measurement of mitochondrial membrane potential (MMP)
reagent used in the protocol.
- Use
- MMP was assessed using the JC-1 fluorescent probe (C2006, Beyotime, China), which selectively accumulates in mitochondria and exhibits a shift in fluorescence emission depending on ΔΨm. Cells were incubated with 5 µM JC-1 for 30 min, washed thoroughly with PBS, and transferred to fresh cultu...
LDH release cytotoxicity assay
reagent used in the protocol.
- Use
- Cytotoxicity was evaluated using a commercial LDH assay kit (C0016, Beyotime, China) following the manufacturer's instructions. After T-BHP treatment, ND7/23 cells were incubated with the supplied LDH reaction mixture, and extracellular LDH activity was measured at 490 nm using a Tecan Spark microplate rea...
Histological staining
reagent used in the protocol.
- Use
- Soft organs and spinal cord samples were cryoprotected in 30 % sucrose for 48 h, embedded in optimal cutting temperature (OCT) compound, and sectioned transversely at 8 µm. After brief air-drying, cryosections were stained following the same HE protocol. After dehydration, clearing, and mounting,...
Microstructural and rheological characterization
The morphology of the HP hydrogel and PDA-HP hydrogel was examined using SEM. Samples were freeze-dried for 48 h, carefully sectioned, and mounted onto conductive adhesive prior to sputter-coating with a thin layer of gold. SEM imaging was performed using a VEGA3 TESCAN instrument (Czech Republic) to assess the...
- Use
- The morphology of the HP hydrogel and PDA-HP hydrogel was examined using SEM. Samples were freeze-dried for 48 h, carefully sectioned, and mounted onto conductive adhesive prior to sputter-coating with a thin layer of gold. SEM imaging was performed using a VEGA3 TESCAN instrument (Czech Republic) to assess the...
Behavioral assessment
Motor coordination and balance were further evaluated using an accelerating rotarod (4-40 rpm over 300 s). Mice were pre-trained for three consecutive days to establish stable baseline latencies. After SCI, the average latency to fall was recorded over three trials per day, with 15-min intervals betw...
- Use
- Motor coordination and balance were further evaluated using an accelerating rotarod (4-40 rpm over 300 s). Mice were pre-trained for three consecutive days to establish stable baseline latencies. After SCI, the average latency to fall was recorded over three trials per day, with 15-min intervals betw...
PDA-HP hydrogel under NIR laser irradiation improves mitochondrial function
Collectively, these results demonstrate that PDA-HP hydrogel under NIR irradiation attenuates oxidative stress, preserves mitochondrial integrity, and improves bioenergetic function, thereby exerting anti-apoptotic and neuroprotective effects after SCI.
- Use
- Collectively, these results demonstrate that PDA-HP hydrogel under NIR irradiation attenuates oxidative stress, preserves mitochondrial integrity, and improves bioenergetic function, thereby exerting anti-apoptotic and neuroprotective effects after SCI.
Photothermal performance measurement
The photothermal behavior of the PDA-HP hydrogel was evaluated under 808 nm near-infrared (NIR) laser irradiation (1.0 W/cm 2 ) to assess its heating capacity under physiologically relevant conditions. Hydrated PDA-HP hydrogel samples (1 mL) were immersed in phosphate-buffered saline (PBS, pH 7....
- Use
- The photothermal behavior of the PDA-HP hydrogel was evaluated under 808 nm near-infrared (NIR) laser irradiation (1.0 W/cm 2 ) to assess its heating capacity under physiologically relevant conditions. Hydrated PDA-HP hydrogel samples (1 mL) were immersed in phosphate-buffered saline (PBS, pH 7....
Photothermal performance measurement
Temperature changes were continuously recorded using both an infrared thermal camera (Fluke TiX560, USA) and a K-type thermocouple probe positioned at the center of the hydrated sample to verify the accuracy of surface and internal temperature measurements. Each heating-cooling cycle was conducted under identical ir...
- Use
- Temperature changes were continuously recorded using both an infrared thermal camera (Fluke TiX560, USA) and a K-type thermocouple probe positioned at the center of the hydrated sample to verify the accuracy of surface and internal temperature measurements. Each heating-cooling cycle was conducted under identical ir...
In vitro cellular experiments
To assess T-BHP-induced cytotoxicity in ND7/23 cells, cell viability was measured using the CCK-8 assay (C0037, Beyotime, China). ND7/23 cells were seeded at 8 × 10 3 cells per well in 96-well plates and allowed to stabilize overnight. Culture medium was then replaced, and cells were e...
- Use
- To assess T-BHP-induced cytotoxicity in ND7/23 cells, cell viability was measured using the CCK-8 assay (C0037, Beyotime, China). ND7/23 cells were seeded at 8 × 10 3 cells per well in 96-well plates and allowed to stabilize overnight. Culture medium was then replaced, and cells were e...
Photothermal treatment and hydrogel co-culture
For co-culture experiments, ND7/23 cells were seeded in 24-well plates (1 × 10 5 cells/well) and incubated with 100 µL of PDA-HP pre-gel solution per well. The mixture was maintained at 37 °C for 10 min to allow complete gelation, forming a thin hydrogel layer over...
- Use
- For co-culture experiments, ND7/23 cells were seeded in 24-well plates (1 × 10 5 cells/well) and incubated with 100 µL of PDA-HP pre-gel solution per well. The mixture was maintained at 37 °C for 10 min to allow complete gelation, forming a thin hydrogel layer over...
Live-dead assay
Cell viability within the hydrogel was assessed using a Live/Dead Viability/Cytotoxicity Kit (C2015S, Beyotime, China) following the manufacturer's instructions. ND7/23 cells were co-cultured with PDA-HP hydrogel for 48 h, after which the staining solution was applied, and samples were incubated at 37...
- Use
- Cell viability within the hydrogel was assessed using a Live/Dead Viability/Cytotoxicity Kit (C2015S, Beyotime, China) following the manufacturer's instructions. ND7/23 cells were co-cultured with PDA-HP hydrogel for 48 h, after which the staining solution was applied, and samples were incubated at 37...
Statistical analysis
Software used for acquisition, scoring, statistics, or reporting.
- Use
- All data are presented as mean ± standard deviation (SD). Statistical analyses were performed using SPSS 24.0 (Chicago, USA). Differences among multiple groups in immunofluorescence and Western blot experiments were assessed by one-way analysis of variance (ANOVA) followed by Tukey's post-hoc te...
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Open quote workflowStep-by-step procedure
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Design and preparation of PDA-HP hydrogel
PDA nanoparticles were synthesized via alkaline oxidative self-polymerization [ ]. Briefly, a mixture of 40 mL absolute ethanol, 90 mL deionized water, and 2 mL ammonium hydroxide (28-30 %) was magnetically stirred in a round-bottom flask. Dopamine hydrochloride (250 mg) dissolved in 10 mL deionized water, was then added, and the reaction was allowed to proceed for 24 h at room temperature. The resulting PDA nanoparticles (average diameter ≈ 193 nm) were collected by centrifugation (15,000 rpm, 10 min), thoroughly washed, and lyophilized.
Design and preparation of PDA-HP hydrogel
Heparin-poloxamer (HP) conjugates were prepared via EDC/NHS-mediated coupling. Poloxamer 407 was first activated with 1.3 mM 4-nitrophenyl chloroformate, followed by reaction with ethylenediamine to produce an amine-terminated intermediate. This intermediate was subsequently reacted with heparin in MES buffer overnight at room temperature. The resulting HP conjugate was purified by extensive dialysis over 3 days and then lyophilized to yield a dry powder.
Determination of steady-state viscosity of HP hydrogel and PDA-HP hydrogel
HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rotational viscometer (NDJ-1S, Shanghai, China) equipped with a T-bar guard and spindle No. 1 was used. The rotor was lowered until the engraved line aligned with the meniscus of the sample. The temperature was increased from 20 °C to 50 °C in increments of 5-7 °C, fully covering the mild photothermal range (37-43 °C) relevant to in vivo PTT conditions. After each 10-min equilibration period, viscosity measurements were recorded at 30 rpm. Each measurement was performed in triplicate, and the mean values were used for statistical analysis.
Photothermal performance measurement
Temperature changes were continuously recorded using both an infrared thermal camera (Fluke TiX560, USA) and a K-type thermocouple probe positioned at the center of the hydrated sample to verify the accuracy of surface and internal temperature measurements. Each heating-cooling cycle was conducted under identical irradiation parameters (808 nm, 1.0 W/cm 2, 10 min per cycle), followed by natural cooling to room temperature before the next cycle, ensuring consistent thermal exposure across all tests.
Photothermal performance measurement
Heating-cooling cycles were repeated six times to evaluate photothermal stability, and temperature-time curves were plotted to assess concentration-dependent heating behavior. For in-vivo thermographic monitoring, infrared imaging was performed at the spinal lesion site during irradiation. The surface temperature was maintained below 43 °C, consistent with the definition of mild photothermal therapy, and no visible tissue damage was observed.
Photothermal treatment and hydrogel co-culture
For co-culture experiments, ND7/23 cells were seeded in 24-well plates (1 × 10 5 cells/well) and incubated with 100 µL of PDA-HP pre-gel solution per well. The mixture was maintained at 37 °C for 10 min to allow complete gelation, forming a thin hydrogel layer over the cells. After 24 h of incubation, the cultures were irradiated with an 808 nm NIR laser (1 W/cm 2 ) for 10 min at a fixed distance of 5 cm. The temperature of the culture medium was continuously monitored with a thermocouple and remained below 43 °C to ensure mild photothermal treatment. Control groups were handled identically without laser exposure.
Animal model of SCI
All experimental procedures were approved by the Institutional Review Board of Gannan Medical University. C57BL/6 mice were purchased from SLAC and housed under controlled conditions at 22-26 °C with 35-55 % relative humidity, with free access to food and water. Female C57BL/6 mice (8 weeks old, 20-22 g) were used in all experiments. Following complete depilation and sequential disinfection of the surgical site with povidone-iodine and 70 % ethanol, general anesthesia was induced with 5 % isoflurane in 1 l/min O 2 and maintained at 2 %. Body temperature was continuously monitored and maintained at 37 °C on a heated surgical platform, and adequate anesthesia was confirmed by the absence of a tail-pinch reflex. A midline skin incision was made, and the paravertebral muscles were bluntly dissected to expose the T9-T10 ve...
Histological staining
For comprehensive histological evaluation, spinal cord, heart, liver, spleen, lung, kidney, and knee-joint (femur-tibia) specimens were fixed in 4 % paraformaldehyde at 4 °C for 48 h. Bones were decalcified in 10 % EDTA (pH 7.4) for 14 days, followed by dehydration, paraffin embedding, and sagittal sectioning at 5 µm. Sections were deparaffinized, rehydrated, and stained with hematoxylin for 5 min and eosin for 2 min.
Measurement outputs
What raw and processed outputs should exist?
For footprint analysis, hind paws were painted with red dye and forepaws with blue dye, and mice traversed a 50 cm runway. Stride length, base of support, and inter-limb co...
- Raw artifact
- Per-run gait capture with paw placement, timing, and stride features for each animal
- Processed artifact
- Cleaned gait metrics table and recovery trend summary across timepoints
- Reported as
- Group comparisons of gait indices, stride metrics, or recovery curves
Motor coordination and balance were further evaluated using an accelerating rotarod (4-40 rpm over 300 s). Mice were pre-trained for three consecutive days to es...
- Raw artifact
- Membrane or gel image with visible bands for target and control proteins
- Processed artifact
- Band quantification and normalized densitometry values
- Reported as
- Relative expression values or fold-change comparisons across groups
HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rota...
- Raw artifact
- Membrane or gel image with visible bands for target and control proteins
- Processed artifact
- Band quantification and normalized densitometry values
- Reported as
- Relative expression values or fold-change comparisons across groups
The photothermal behavior of the PDA-HP hydrogel was evaluated under 808 nm near-infrared (NIR) laser irradiation (1.0 W/cm 2 ) to assess its heating capacity under ph...
- Raw artifact
- Membrane or gel image with visible bands for target and control proteins
- Processed artifact
- Band quantification and normalized densitometry values
- Reported as
- Relative expression values or fold-change comparisons across groups
Analysis plan
How should the outputs become interpretable results?
Acquisition
Collect the raw assay or blot output and retain identifiers for each sample and experimental group.
inferred from protocolPreprocessing / cleaning
The morphology of the HP hydrogel and PDA-HP hydrogel was examined using SEM.
from paperScoring or quantification
Quantify the primary readouts for this experiment: For footprint analysis, hind paws were painted with red dye and forepaws with blue dye, and mice traversed a 50 cm runway. Stride length, base of support, and inter-limb co...; Motor coordination and balance were further evaluated using an accelerating rotarod (4-40 rpm over 300 s). Mice were pre-trained for three consecutive days to es...; HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rota...; The photothermal behavior of the PDA-HP hydrogel was evaluated under 808 nm near-infrared (NIR) laser irradiation (1.0 W/cm 2 ) to assess its heating capacity under ph....
from paperNormalization
Normalize expression or signal values against the stated control or loading reference before comparing groups.
inferred from protocolStatistical comparison
The morphology of the HP hydrogel and PDA-HP hydrogel was examined using SEM. Samples were freeze-dried for 48 h, carefully sectioned, and mounted onto conductive adhesive...; HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rota...; All data are presented as mean ± standard deviation (SD). Statistical analyses were performed using SPSS 24.0 (Chicago, USA). Differences among multiple groups in...; PDA-HP hydrogel exhibited robust and tunable photothermal performance under 808 nm irradiation (1.0 W/cm 2 ). Photothermal heating profiles ( A) were obtained from hyd...
from paperReporting output
Report representative outputs alongside summary comparisons for For footprint analysis, hind paws were painted with red dye and forepaws with blue dye, and mice traversed a 50 cm runway. Stride length, base of support, and inter-limb co..., Motor coordination and balance were further evaluated using an accelerating rotarod (4-40 rpm over 300 s). Mice were pre-trained for three consecutive days to es..., HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rota..., The photothermal behavior of the PDA-HP hydrogel was evaluated under 808 nm near-infrared (NIR) laser irradiation (1.0 W/cm 2 ) to assess its heating capacity under ph....
inferred from protocolStructured statistical methods
The morphology of the HP hydrogel and PDA-HP hydrogel was examined using SEM. Samples were freeze-dried for 48 h, carefully sectioned, and mounted onto conductive adhesive...; HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rota...; All data are presented as mean ± standard deviation (SD). Statistical analyses were performed using SPSS 24.0 (Chicago, USA). Differences among multiple groups in...; PDA-HP hydrogel exhibited robust and tunable photothermal performance under 808 nm irradiation (1.0 W/cm 2 ). Photothermal heating profiles ( A) were obtained from hyd...
source structuredSource and audit
What supports the facts on this page?
Evidence quotes (8)
PDA nanoparticles were synthesized via alkaline oxidative self-polymerization [ ]. Briefly, a mixture of 40 mL absolute ethanol, 90 mL deionized water, and 2 mL ammonium hydroxide (28-30 %) was magnetically stirred in a round-bottom flask. Dopamine hydrochloride (250 mg) dissolved in 10 mL deionized water, was then added, and the reaction was allowed to proceed for 24 h at room temperature. The resulting PDA nanoparticles (average diameter ≈ 193 nm) were collected by centrifugation (15,000 rpm, 10 min), thoroughly washed, and lyophilized.
Heparin-poloxamer (HP) conjugates were prepared via EDC/NHS-mediated coupling. Poloxamer 407 was first activated with 1.3 mM 4-nitrophenyl chloroformate, followed by reaction with ethylenediamine to produce an amine-terminated intermediate. This intermediate was subsequently reacted with heparin in MES buffer overnight at room temperature. The resulting HP conjugate was purified by extensive dialysis over 3 days and then lyophilized to yield a dry powder.
HP hydrogel and PDA-HP hydrogel samples (60 mL each) were equilibrated in a thermostatic bath with a temperature control precision of ±0.1 °C. A digital rotational viscometer (NDJ-1S, Shanghai, China) equipped with a T-bar guard and spindle No. 1 was used. The rotor was lowered until the engraved line aligned with the meniscus of the sample. The temperature was increased from 20 °C to 50 °C in increments of 5-7 °C, fully covering the mild photothermal range (37-43 °C) relevant to in vivo PTT conditions. After each 10-min equilibration period, viscosity measurements were recorded at 30 rpm. Each measurement was performed in triplicate, and the mean values were used for statistical analysis.
Temperature changes were continuously recorded using both an infrared thermal camera (Fluke TiX560, USA) and a K-type thermocouple probe positioned at the center of the hydrated sample to verify the accuracy of surface and internal temperature measurements. Each heating-cooling cycle was conducted under identical irradiation parameters (808 nm, 1.0 W/cm 2, 10 min per cycle), followed by natural cooling to room temperature before the next cycle, ensuring consistent thermal exposure across all tests.
Heating-cooling cycles were repeated six times to evaluate photothermal stability, and temperature-time curves were plotted to assess concentration-dependent heating behavior. For in-vivo thermographic monitoring, infrared imaging was performed at the spinal lesion site during irradiation. The surface temperature was maintained below 43 °C, consistent with the definition of mild photothermal therapy, and no visible tissue damage was observed.
For co-culture experiments, ND7/23 cells were seeded in 24-well plates (1 × 10 5 cells/well) and incubated with 100 µL of PDA-HP pre-gel solution per well. The mixture was maintained at 37 °C for 10 min to allow complete gelation, forming a thin hydrogel layer over the cells. After 24 h of incubation, the cultures were irradiated with an 808 nm NIR laser (1 W/cm 2 ) for 10 min at a fixed distance of 5 cm. The temperature of the culture medium was continuously monitored with a thermocouple and remained below 43 °C to ensure mild photothermal treatment. Control groups were handled identically without laser exposure.
All experimental procedures were approved by the Institutional Review Board of Gannan Medical University. C57BL/6 mice were purchased from SLAC and housed under controlled conditions at 22-26 °C with 35-55 % relative humidity, with free access to food and water. Female C57BL/6 mice (8 weeks old, 20-22 g) were used in all experiments. Following complete depilation and sequential disinfection of the surgical site with povidone-iodine and 70 % ethanol, general anesthesia was induced with 5 % isoflurane in 1 l/min O 2 and maintained at 2 %. Body temperature was continuously monitored and maintained at 37 °C on a heated surgical platform, and adequate anesthesia was confirmed by the absence of a tail-pinch reflex. A midline skin incision was made, and the paravertebral muscles were bluntly dissected to expose the T9-T10 vertebrae. The T9 spinous process, angled caudally, and the neutral to slightly caudally tilted T10 process served as anatomical landmarks. Following complete laminectomy at T9-T10, the spinal cord was fully exposed. A moderate contusion was induced at the midline using a 10 g stainless-steel rod...
For comprehensive histological evaluation, spinal cord, heart, liver, spleen, lung, kidney, and knee-joint (femur-tibia) specimens were fixed in 4 % paraformaldehyde at 4 °C for 48 h. Bones were decalcified in 10 % EDTA (pH 7.4) for 14 days, followed by dehydration, paraffin embedding, and sagittal sectioning at 5 µm. Sections were deparaffinized, rehydrated, and stained with hematoxylin for 5 min and eosin for 2 min.
Machine-readable layer
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"text": "PDA nanoparticles were synthesized via alkaline oxidative self-polymerization [ ]. Briefly, a mixture of 40 mL absolute ethanol, 90 mL deionized water, and 2 mL ammonium hydroxide (28-30 %) was magnetically stirred in a round-bottom flask. Dopamine hydrochloride (250 mg) dissolved in 10 mL deionized water, was then added, and the reaction was allowed to proceed for 24 h at room temperature. The resulting PDA nanoparticles (average diameter ≈ 193 nm) were collected by centrifugation (15,000 rpm, 10 min), thoroughly washed, and lyophilized."
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"text": "Heparin-poloxamer (HP) conjugates were prepared via EDC/NHS-mediated coupling. Poloxamer 407 was first activated with 1.3 mM 4-nitrophenyl chloroformate, followed by reaction with ethylenediamine to produce an amine-terminated intermediate. This intermediate was subsequently reacted with heparin in MES buffer overnight at room temperature. The resulting HP conjugate was purified by extensive dialysis over 3 days and then lyophilized to yield a dry powder."
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"text": "Heating-cooling cycles were repeated six times to evaluate photothermal stability, and temperature-time curves were plotted to assess concentration-dependent heating behavior. For in-vivo thermographic monitoring, infrared imaging was performed at the spinal lesion site during irradiation. The surface temperature was maintained below 43 °C, consistent with the definition of mild photothermal therapy, and no visible tissue damage was observed."
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"headline": "Dual-responsive PDA-HP hydrogel enables mitochondria-targeted mild photothermal therapy for spinal cord repair",
"datePublished": "2026",
"author": [
{
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"name": "Yi Li"
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"name": "Jiaxuan Hu"
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"name": "Bing Ran"
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"@type": "Person",
"name": "Huisheng Zhong"
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"@type": "Person",
"name": "Nayin Zhong"
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"@type": "Person",
"name": "Yi Zhong"
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"name": "Xinyu Fu"
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"name": "Xinying Liu"
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"name": "Guanghua Wu"
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{
"@type": "Person",
"name": "Qinwen Zhong"
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"name": "Juan Li"
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"identifier": "10.1016/j.mtbio.2026.102783"
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"name": "Dual-responsive PDA-HP hydrogel enables mitochondria-targeted mild photothermal therapy for spinal cord repair methods",
"item": "https://replicatescience.com/experiments/dual-responsive-pda-hp-hydrogel-enables-mitochondria-targeted-mild-photothermal-therapy-for-spinal-cord-repair-methods-yi-li-pmc12856442/dual-responsive-pda-hp-hydrogel-enables-mitochondria-targeted-mild-photothermal-"
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