# Alginate-Chitosan Microencapsulated Cells for Improving CD34+
## 4 Conclusions  
A non-toxic double-layered microcapsule has been successfully fabricated with alginate-chitosan to encapsulate human CD34\({}^{+}\) progenitor cells. The microcapsules did not pose any toxicity to external cells. Cell proliferation and progenitor maintenance were significantly improved when the cells from unrelated donors were cultured with CD34\({}^{+}\) cell-loaded microcapsules. The thrombopoietin-induced megakaryocytic differentiation was amplified when the cells were co-cultured with cell-loaded microcapsules, while it was repressed when co-cultured with non-encapsulated cells. Our study is the first proof-of-concept that microencapsulation can be utilized to deliver paracrine factors for ex vivo expansion of HLA-unmatched CD34\({}^{+}\) progenitors.  
The following are available online at [[https://www.mdpi.com/article/10.3390/app11177887/s1](https://www.mdpi.com/article/10.3390/app11177887/s1)]([https://www.mdpi.com/article/10.3390/app11177887/s1](https://www.mdpi.com/article/10.3390/app11177887/s1)), Figure S1: A. Illustration of co-culture system of microencapsulated CD34\({}^{+}\) cells (6 \(\times\) 10\({}^{3}\) cells/well) with bare CD34\({}^{+}\) cells from unrelated donors. B. Viable cell concentration of bare cells after co-culturing for 8 days, Figure S2: Fold expansions of CD34\({}^{+}\) cells (lower well) on day 8 post-culturing with and without cell-loaded microcapsules (3 \(\times\) 10\({}^{4}\) cells/well), Figure S3: A. Viable cell concentration of bare cells (lower well) on day 8. B. Ratio of CD34\({}^{+}\) cell population on day 8. Bare cells and microencapsulated cells (Donor 5, upper well) were 3.0 \(\times\) 10\({}^{4}\) cells/well. Initial seeding of bare cells (Donor 6; lower well) was 2.5 \(\times\) 10\({}^{4}\) cells/ml. Donor 5 and 6 were unrelated patients. Figure S4: Effect of thrombopoietin (TPO) for CD34\({}^{+}\) cells cultured on platelet-lysate-(PL)-supplemented media, Figure S5: The CD41\({}^{+}\) cell population of bare cells (lower well) after 8-day monoculture or co-cultures in thrombopoietin-supplemented media; Illustration of co-culture systems with microcapsule-bioreactor and membrane insert.  
R.W.N.: Conceptualization, Methodology, Investigation, Data Curation, Writing, Visualization, Supervision. R.D.C.: Methodology, Investigation, Resources. G.P.: Resources. D.A.: Formal analysis, Validation. W.M.: Formal analysis, Writing-Review and Editing. M.K.: Writing-Review and Editing. R.D.A.: Resources. All authors have read and agreed to the published version of the manuscript.  
This work was partially supported by Q1Q2 Scheme Research Grant (Hibah Publikasi Artikel di Jurnal International Kuartil Q1 dan Q2 (Q1Q2) No. NKB-0232/UN2.R3.1/HKP.05.00/2019) and P5 Grant (Program Pendanaan Percangan dan Pengembangan Purwarupa) No. PKS-13/UN2.INV /HKP05/2020 from Universitas Indonesia awarded to Dr. [PERSON].  
Ethical clearance for this study was ratified by the Ethics Committee of the Faculty of Medicine, Universitas Indonesia--Dr. Cipto Mangunkusumo General Hospital.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
All data generated or analysed during this study are included in this published article and its supplementary information files.  
The authors thank Cipto Mangunkusumo General Hospital (RSCM) for facilitating UCB collection, [PERSON] and [PERSON] for technical support.  
The authors declare no conflict of interest.