# Biodegradable Mg alloy modified with bioactive exosomes for cardiovascular stent application
Researcher: Ge Zhang
Chinese name: 张格
ORCID identity anchor: https://orcid.org/0000-0002-3116-3246
Canonical researcher: https://drgezhang.com/#person
Journal: Journal of Magnesium and Alloys
Year: 2023
Type: Article
DOI: 10.1016/j.jma.2023.05.007
Canonical page: https://drgezhang.com/papers/doi-10-1016-j-jma-2023-05-007.html
Markdown record: https://drgezhang.com/papers/doi-10-1016-j-jma-2023-05-007.md
## Full Authors
1. Ya-chen Hou
2. Jing-an Li
3. Chang Cao
4. Chang Su
5. Zhen Qin
6. Ge Zhang
7. Jia-cheng Guo
8. Jun-nan Tang
9. Jin-ying Zhang
10. Shao-kang Guan
## Research & review context
### Research fields
- Cardiovascular biomaterials
- Biodegradable stent research
### Review topics
- Exosome-functionalized magnesium alloys
- Preclinical endothelial compatibility
### Scientific role
Coating-material development with endothelial/immune cell tests and small rat abdominal-aorta wire implantation.
### Evidence position
Preclinical physicochemical and cell readouts plus short animal histology; no human-stent outcome validation.
### Related concepts
- MgF2–polydopamine coating
- Exosome surface release
- Rat aortic wire implantation
### Possible citation contexts
- Reviews comparing biologically functionalized metallic cardiovascular implant surfaces.
- Preclinical biomaterial reports distinguishing cell-level endothelial surrogates from clinical restenosis outcomes.
Possible literature-review contexts, not evidence of existing citations. Read the findings and Evidence Scope before citing the original article.
## Evidence Scale
**Biodegradable Mg alloy modified with bioactive exosomes for cardiovascular stent application**
A Mg-Zn-Y-Nd alloy bearing MgF2, polydopamine and an exosome-containing coating showed improved corrosion-related test readouts and endothelial-compatible cell behaviors in preclinical material and cell assays. A small rat abdominal-aorta wire-implant experiment provided descriptive 21-day histology. The study did not test a marketed stent in humans or establish restenosis reduction or clinical patency.
| Evidence | Value |
| --- | --- |
| Rat implantation | 15 SD rats; three wire groups of 5 rats each |
| Rat follow-up figure | H&E imaging at 21 days post-implantation |
| Wire size | 1 mm diameter × 10 mm length, not a clinical marketed stent |
| Coating composition | MgF2, polydopamine and a human-blood-derived exosome preparation |
| Surface exosome release | Reported approximately 5–7-day release in experimental conditions |
### Counting note
Five rats per implant group are animal counts, distinct from in-vitro replicate values, cells, particle counts and fabricated material samples. Descriptive histology does not provide an independently quantified clinical patency outcome.
## Research Question
Can a surface-bound exosome/polydopamine coating on biodegradable magnesium alloy balance corrosion resistance with vascular-cell responses relevant to stent development, and how far do the supporting models justify translation?
## Author Evidence Summary
The researchers created MgF2–PDA/exosome-coated Mg-Zn-Y-Nd alloy, measured morphology and corrosion, compared blood-contact and vascular-cell behavior, examined release/uptake in cultured cells, and implanted three wire configurations into rat abdominal aortas. The only published Figure S1 supplement cited for complete immunoblot views was not obtained; this evidence summary does not draw a result from it.
## Key Findings
### KF1: Exosome-associated coating and particle characteristics were documented using material-level tests.
Context: Exosome identity-related Western blot complete images were cited as missing Figure S1; no conclusion requires interpretation of that unavailable supplement.
| Evidence | Value |
| --- | --- |
| Alloy | Mg-Zn-Y-Nd modified with MgF2 and PDA/exosome |
| Particle size from NTA | Reported 50–150 nm distribution |
| Source completeness | Full Western-blot Figure S1 supplement unavailable; excluded from validated findings |
Source locator: Publisher VOR PDF: Abstract and Results §3.1 Exosome characterization, PDF pp.1,6 (printed pp.4988,4993); main Figure 2. The full Western blot is referred to as Figure S1 and was not available in the source pack.
### KF2: The modified surface showed different corrosion characteristics from bare magnesium alloy in laboratory immersion/electrochemical tests.
Context: Corrosion outcomes reflect specified HBSS and bench-test conditions, not confirmed long-term human implant degradation or clinical durability.
| Evidence | Value |
| --- | --- |
| Test domain | Electrochemical behavior, pH, hydrogen evolution and weight loss |
| Material comparison | Bare Mg alloy, MgF2, MgF2–PDA and MgF2–PDA/exosome |
| Result direction | Article reports improved resistance with modified coating |
Source locator: Publisher VOR PDF: Methods §2.4 Corrosion resistance, Results §3.3 Corrosion resistance; Figures 3–5; PDF pp.3–9 (printed 4990–4996).
### KF3: MgF2–PDA/exosome surfaces were associated with improved cultured endothelial readouts.
Context: Bench-cell observations are surrogate readouts relevant to endothelialization, not a measurement of human-stent clinical restenosis or healing.
| Evidence | Value |
| --- | --- |
| Endothelial assays | Adhesion, CCK-8 growth proxy, CD31 staining, NO release and migration |
| Reported 3-day surface cell density | Approximately 1.8×10^5 cells/cm² on coated surface versus 2×10^4 on bare alloy (article-described comparison) |
| Figure-level replicates | Figure 8B/C: n=6; Figure 8D: n=3 |
Source locator: Publisher VOR PDF: Methods §§2.8–2.10, Results §3.7 vascular endothelial cell responses; Figure 8A–H; PDF pp.4–5 and 10–12 (printed 4991–4992 and 4997–4999).
### KF4: Inflammatory and smooth-muscle cell readouts differed under the coated-material conditions.
Context: Macrophage TNF-α/CD206 or smooth-muscle α-SMA/OPN expression is not a directly tested causal anti-restenosis mechanism in human vessels.
| Evidence | Value |
| --- | --- |
| Macrophage assessment | TNF-α, CD206 and reactive oxygen species in extract-solution culture |
| Smooth-muscle assessment | α-SMA, osteopontin and cell competition assays |
| Model domain | In-vitro phenotype and compatibility metrics |
Source locator: Publisher VOR PDF: Results §§3.6–3.8, Figures 7, 9 and 10; PDF pp.9–14 (printed 4996–5001).
### KF5: Exosome-associated signals were observed in cultured endothelial uptake and release assays.
Context: Fluorescence overlap with cellular organelles indicates reported localization, not a proven cargo-mediated causal pathway or controlled therapeutic dose.
| Evidence | Value |
| --- | --- |
| Release window | Approximately 5–7 days in the tested coating system |
| Cellular colocalization | Reported overlap with lysosomal and mitochondrial fluorescent markers |
| Interpretation | Exploratory uptake/localization observations |
Source locator: Publisher VOR PDF: Methods §§2.10–2.11, Results §3.8 Release and uptake of exosomes, Figure 11; PDF pp.5–6 and 14–15 (printed 4992–4993 and 5001–5002).
### KF6: A short rat aortic wire-implant experiment showed descriptive vessel-wall histological differences.
Context: The animal intervention used wires rather than clinical coronary stents; the presented H&E sections do not independently establish quantitative lumen patency, thrombosis prevention or long-term safety.
| Evidence | Value |
| --- | --- |
| Rodent design | 15 SD rats; bare-Mg, MgF2 and MgF2–PDA/exosome wire groups, n=5 each |
| Site and time | Rat abdominal aorta; 21-day histology |
| Endpoint limitation | Qualitative H&E representative sections only in Figure 12 |
Source locator: Publisher VOR PDF: Methods §2.12 The SD rat experiment, PDF p.6 (printed 4993); Results and Figure 12, PDF pp.15–16 (printed 5002–5003).
## How the Study Was Done
### Study profile
- Study Design: Surface-modified biodegradable magnesium alloy development with physicochemical testing, in-vitro platelet/macrophage/endothelial/smooth-muscle assays and small rodent abdominal-aorta wire implantation.
- Evidence Type: Preclinical material characterization and cell behavior with qualitative vascular histology; no human randomized trial or implanted clinical coronary stent.
- Population: Mg-Zn-Y-Nd test coupons/wires; vascular and immune cell experiments; 15 adult SD rats implanted with wire variants in abdominal aorta.
- Primary Endpoint: Corrosion-related testing and coating biocompatibility under the reported laboratory conditions.
- Secondary Endpoint: Endothelial adhesion/proliferation and NO/CD31 readouts; macrophage and smooth-muscle phenotypes; release/uptake observations; 21-day rat tissue histology.
- External dataset evaluation: No
- Data modalities: Material surface morphology and electrochemical corrosion assays, Exosome particle characterization and cell uptake imaging, Blood-contact and macrophage assays, Vascular endothelial and smooth-muscle cell assays, Rat abdominal-aorta wire-implant H&E histology
## What This Study Adds
- Connects material corrosion testing with endothelial, macrophage, smooth-muscle and short animal vascular-tissue readouts.
- Establishes a scoped preclinical basis for magnesium-alloy exosome-coating research while avoiding claims of human restenosis prevention.
## Evidence Scope
### Supports
- Modified material surfaces change measured corrosion and vascular-cell readouts under the stated in-vitro conditions.
- The article reports a small rat aortic wire implantation study with histological observations after 21 days.
- The design offers preclinical hypotheses about biomaterial surface engineering and compatibility.
### Does Not Establish
- Clinical efficacy, safety, coronary stent patency, thrombosis reduction or restenosis benefit in humans.
- A rigorously measured long-term implantation outcome, given representative rat tissue images only.
- A confirmed exosomal molecular cargo mechanism of endothelial repair.
- Any result relying on the missing full Western-blot Figure S1.
- Evidence that surface endothelial cell density in vitro is equivalent to in-vivo reendothelialization of human stents.
### Limitations
- Missing formal supplementary Figure S1 prevents independent checking of the complete immunoblot panel; no result is attributed to that file.
- The preclinical implant was wire placement in rat abdominal aorta, not an implanted human coronary stent.
- Figure 12 shows qualitative histology at 21 days; no clinical or long-term luminal patency study is demonstrated.
- Corrosion, cell proliferation, platelet adhesion and release data depend on specific in-vitro testing protocols.
- The official volume/issue is Journal of Magnesium and Alloys 12(12) (2024), pages 4988–5004; article first online in 2023. Existing bibliographic site year remains protected.
## When This Study Is Useful to Cite
### CU1: Which coating evidence supports preclinical vascular compatibility?
Bench tests, cell culture and descriptive rat histology with narrow outcome scope.
Evidence: [KF2](#kf2), [KF3](#kf3), [KF6](#kf6)
### CU2: What does the exosome-coated magnesium study show in animals?
Small rat aortic wire histology; not clinical coronary stent efficacy.
Evidence: [KF6](#kf6)
### CU3: Which source limitation affects independent replication?
Unobtained original Figure S1 Western blot image; excluded from accepted claims.
Evidence: [KF1](#kf1)
## What This Study Should Not Be Cited to Claim
- Clinical efficacy, safety, coronary stent patency, thrombosis reduction or restenosis benefit in humans.
- A rigorously measured long-term implantation outcome, given representative rat tissue images only.
- A confirmed exosomal molecular cargo mechanism of endothelial repair.
- Any result relying on the missing full Western-blot Figure S1.
- Evidence that surface endothelial cell density in vitro is equivalent to in-vivo reendothelialization of human stents.
## Evidence Matrix
### KF1: Exosome-associated coating and particle characteristics were documented using material-level tests.
- Context: Exosome identity-related Western blot complete images were cited as missing Figure S1; no conclusion requires interpretation of that unavailable supplement.
- Finding: Exosome-associated coating and particle characteristics were documented using material-level tests. Alloy: Mg-Zn-Y-Nd modified with MgF2 and PDA/exosome; Particle size from NTA: Reported 50–150 nm distribution; Source completeness: Full Western-blot Figure S1 supplement unavailable; excluded from validated findings
- Evidence Level: Exosome identity-related Western blot complete images were cited as missing Figure S1; no conclusion requires interpretation of that unavailable supplement.
- Scope: Exosome identity-related Western blot complete images were cited as missing Figure S1; no conclusion requires interpretation of that unavailable supplement.
- Source Locator: Publisher VOR PDF: Abstract and Results §3.1 Exosome characterization, PDF pp.1,6 (printed pp.4988,4993); main Figure 2. The full Western blot is referred to as Figure S1 and was not available in the source pack.
- Evidence refs: [KF1](#kf1)
### KF2: The modified surface showed different corrosion characteristics from bare magnesium alloy in laboratory immersion/electrochemical tests.
- Context: Corrosion outcomes reflect specified HBSS and bench-test conditions, not confirmed long-term human implant degradation or clinical durability.
- Finding: The modified surface showed different corrosion characteristics from bare magnesium alloy in laboratory immersion/electrochemical tests. Test domain: Electrochemical behavior, pH, hydrogen evolution and weight loss; Material comparison: Bare Mg alloy, MgF2, MgF2–PDA and MgF2–PDA/exosome; Result direction: Article reports improved resistance with modified coating
- Evidence Level: Corrosion outcomes reflect specified HBSS and bench-test conditions, not confirmed long-term human implant degradation or clinical durability.
- Scope: Corrosion outcomes reflect specified HBSS and bench-test conditions, not confirmed long-term human implant degradation or clinical durability.
- Source Locator: Publisher VOR PDF: Methods §2.4 Corrosion resistance, Results §3.3 Corrosion resistance; Figures 3–5; PDF pp.3–9 (printed 4990–4996).
- Evidence refs: [KF2](#kf2)
### KF3: MgF2–PDA/exosome surfaces were associated with improved cultured endothelial readouts.
- Context: Bench-cell observations are surrogate readouts relevant to endothelialization, not a measurement of human-stent clinical restenosis or healing.
- Finding: MgF2–PDA/exosome surfaces were associated with improved cultured endothelial readouts. Endothelial assays: Adhesion, CCK-8 growth proxy, CD31 staining, NO release and migration; Reported 3-day surface cell density: Approximately 1.8×10^5 cells/cm² on coated surface versus 2×10^4 on bare alloy (article-described comparison); Figure-level replicates: Figure 8B/C: n=6; Figure 8D: n=3
- Evidence Level: Bench-cell observations are surrogate readouts relevant to endothelialization, not a measurement of human-stent clinical restenosis or healing.
- Scope: Bench-cell observations are surrogate readouts relevant to endothelialization, not a measurement of human-stent clinical restenosis or healing.
- Source Locator: Publisher VOR PDF: Methods §§2.8–2.10, Results §3.7 vascular endothelial cell responses; Figure 8A–H; PDF pp.4–5 and 10–12 (printed 4991–4992 and 4997–4999).
- Evidence refs: [KF3](#kf3)
### KF4: Inflammatory and smooth-muscle cell readouts differed under the coated-material conditions.
- Context: Macrophage TNF-α/CD206 or smooth-muscle α-SMA/OPN expression is not a directly tested causal anti-restenosis mechanism in human vessels.
- Finding: Inflammatory and smooth-muscle cell readouts differed under the coated-material conditions. Macrophage assessment: TNF-α, CD206 and reactive oxygen species in extract-solution culture; Smooth-muscle assessment: α-SMA, osteopontin and cell competition assays; Model domain: In-vitro phenotype and compatibility metrics
- Evidence Level: Macrophage TNF-α/CD206 or smooth-muscle α-SMA/OPN expression is not a directly tested causal anti-restenosis mechanism in human vessels.
- Scope: Macrophage TNF-α/CD206 or smooth-muscle α-SMA/OPN expression is not a directly tested causal anti-restenosis mechanism in human vessels.
- Source Locator: Publisher VOR PDF: Results §§3.6–3.8, Figures 7, 9 and 10; PDF pp.9–14 (printed 4996–5001).
- Evidence refs: [KF4](#kf4)
### KF5: Exosome-associated signals were observed in cultured endothelial uptake and release assays.
- Context: Fluorescence overlap with cellular organelles indicates reported localization, not a proven cargo-mediated causal pathway or controlled therapeutic dose.
- Finding: Exosome-associated signals were observed in cultured endothelial uptake and release assays. Release window: Approximately 5–7 days in the tested coating system; Cellular colocalization: Reported overlap with lysosomal and mitochondrial fluorescent markers; Interpretation: Exploratory uptake/localization observations
- Evidence Level: Fluorescence overlap with cellular organelles indicates reported localization, not a proven cargo-mediated causal pathway or controlled therapeutic dose.
- Scope: Fluorescence overlap with cellular organelles indicates reported localization, not a proven cargo-mediated causal pathway or controlled therapeutic dose.
- Source Locator: Publisher VOR PDF: Methods §§2.10–2.11, Results §3.8 Release and uptake of exosomes, Figure 11; PDF pp.5–6 and 14–15 (printed 4992–4993 and 5001–5002).
- Evidence refs: [KF5](#kf5)
### KF6: A short rat aortic wire-implant experiment showed descriptive vessel-wall histological differences.
- Context: The animal intervention used wires rather than clinical coronary stents; the presented H&E sections do not independently establish quantitative lumen patency, thrombosis prevention or long-term safety.
- Finding: A short rat aortic wire-implant experiment showed descriptive vessel-wall histological differences. Rodent design: 15 SD rats; bare-Mg, MgF2 and MgF2–PDA/exosome wire groups, n=5 each; Site and time: Rat abdominal aorta; 21-day histology; Endpoint limitation: Qualitative H&E representative sections only in Figure 12
- Evidence Level: The animal intervention used wires rather than clinical coronary stents; the presented H&E sections do not independently establish quantitative lumen patency, thrombosis prevention or long-term safety.
- Scope: The animal intervention used wires rather than clinical coronary stents; the presented H&E sections do not independently establish quantitative lumen patency, thrombosis prevention or long-term safety.
- Source Locator: Publisher VOR PDF: Methods §2.12 The SD rat experiment, PDF p.6 (printed 4993); Results and Figure 12, PDF pp.15–16 (printed 5002–5003).
- Evidence refs: [KF6](#kf6)
## Q&A
### Was this a human cardiovascular stent trial?
No. The reported work used material tests, cultured cells and 15 rats implanted with alloy wires in the abdominal aorta. No treated human patients or clinical efficacy endpoint were reported.
Evidence: KF6
### What is the coating made from?
An Mg-Zn-Y-Nd alloy had an MgF2 layer, an adhesive polydopamine layer and an exosome-containing surface treatment.
Evidence: KF1
### What vascular endothelial outcomes were assessed?
The paper reports cell adhesion/growth, CD31, nitric oxide and migration assays under culture conditions, with differences between coated and bare material groups.
Evidence: KF3
### How long were the exosome-associated release effects observed?
The article reports an experimental release window of approximately 5–7 days; this should not be interpreted as an established clinical delivery period.
Evidence: KF5
### What did the 21-day animal experiment measure?
Fifteen rats were assigned across three abdominal-aorta wire conditions, with representative H&E tissue sections at day 21. This is not quantitative human stent patency evidence.
Evidence: KF6
### Is every figure-level source available?
No. The original Figure S1 for full Western blot imaging was not in the source pack, so its content is not used as verified evidence in this summary.
Evidence: KF1
## Concepts & Entities
### Device Materials
Biodegradable magnesium alloy, MgF2–PDA/exosome coating, Vascular scaffold surfaces
### Preclinical Biology
Endothelialization surrogates, Macrophage phenotype, Smooth muscle cell markers
### Evidence Levels
Corrosion bench tests, Rat aortic wire histology, Supplement Figure S1 absent
## Related Research
- [Three-dimensional bioprinting of artificial blood vessel: Process, bioinks, and challenges](https://drgezhang.com/papers/doi-10-18063-ijb-740.html) — A different vascular biomaterial engineering review, focused on three-dimensional printed vessels rather than biodegradable metallic stent-wire coatings. (DOI: 10.18063/ijb.740)
## Publication & Provenance
- DOI: https://doi.org/10.1016/j.jma.2023.05.007
- Doi Url: https://doi.org/10.1016/j.jma.2023.05.007
- Publisher: https://www.sciopen.com/article/10.1016/j.jma.2023.05.007
- License: CC BY-NC-ND 4.0 in publisher version-of-record PDF; original evidence summary only, without adapting/reproducing article text, figures or tables.
- License Url: https://creativecommons.org/licenses/by-nc-nd/4.0/
- Version Of Record: Journal of Magnesium and Alloys 12(12) (2024): 4988–5004; article online 27 June 2023; DOI 10.1016/j.jma.2023.05.007. Existing repository year 2023 is preserved.
- Source Artifacts: Official SciOpen VOR 17-page PDF and Figures 1–12; supplementary Figure S1 still unavailable.
- Source Limitation: Cannot verify the full Western blot panel referenced as Figure S1; all accepted KFs derive from accessible VOR material without use of that image.
- Clinical Boundary: Bench and animal observations only; no human clinical safety, restenosis or stent-outcome evidence.
## Evidence-page notice
This is an original, noncommercial evidence synthesis of a preclinical biomaterials study, not a clinical stent trial. The unavailable Supplementary Figure S1 is disclosed and no claim is based on its uninspected contents.
## Links
- DOI: https://doi.org/10.1016/j.jma.2023.05.007
- HTML page: https://drgezhang.com/papers/doi-10-1016-j-jma-2023-05-007.html
- Google Scholar query: https://scholar.google.com/scholar?q=%22Biodegradable%20Mg%20alloy%20modified%20with%20bioactive%20exosomes%20for%20cardiovascular%20stent%20application%22
- ORCID: https://orcid.org/0000-0002-3116-3246