Tissue printing for engineering transplantable human parathyroid patch

[helvella]

An interesting development in managing one of the problems of thyroid surgery - damage to the parathyroid glands.

Biofabrication

. 2021 Apr 13.

doi: 10.1088/1758-5090/abf740. Online ahead of print.

Tissue printing for engineering transplantable human parathyroid patch to improves parathyroid engraftment, integration, and hormone secretion in vivo

Hyeong Won Yu 1 , Byoung Soo Kim 2 , Jae Yeon Lee 3 , Keunchul Lee 4 , Minjun Ahn 5 , Jinah Jang 6 , Dong-Woo Cho 7 , June Young Choi 1

Affiliations

• PMID: 33848986

• DOI: 10.1088/1758-5090/abf740

Abstract

During thyroid surgery, some parathyroid glands fail to maintain their function, therefore, they are unavoidably detached from the patient. For the purpose of re-preservation of the function, they are minced into small segments and transplanted into the fat or muscle layer. Yet, this method of auto-grafting the parathyroid glands is frequently unsuccessful due to its poor interaction and engraftment with the native tissue, eventually leading to the dysfunction of the parathyroid hormone (PTH) secretion. In this study, we suggest a methodology to restore parathyroid activity through the introduction of the "tissue printing" concept. Parathyroid glands of patients with secondary hyperparathyroidism were minced into the fragments smaller than 0.5 × 0.5 mm, which is in common with the traditional surgical method. These parathyroid tissues (PTs) were uniformly mixed with the adipose-derived decellularized extracellular matrix (adECM) bioink that protects the PTs from hostile in vivo environments and promote initial engraftment. PTs-encapsulated adECM bioink (PTs-adECM) was then printed onto the pre-designed polycaprolactone (PCL) mesh to produce patch-type PTs construct, which functions as a mechanical support to further enhance long-term in vivo stability. The engineered patch was transplanted subcutaneously into rats and harvested after 4 weeks. In vivo results showed that the engineered patches were well engrafted and stabilized in their original position for 4 weeks as compared with PTs only. Immunohistochemistry results further revealed that the concentration of PTH was approximately 2.5-fold greater in rats engrafted in the patch. Taken together, we envision that the novel concept "tissue printing" over cell printing could provide a closer step towards clinical applications of 3D bioprinting to solve the unmet need for parathyroid surgery method.

Keywords: 3D bioprinting; parathyroid autotransplantation; parathyroid engraftment and hormone secretion; tissue printing.

pubmed.ncbi.nlm.nih.gov/338...

[Rapunzel]

I'd luuurve a new thyroid via 3D bioprinting...can't be too far away if this is in the pipeline, surely. Thanks, Rod x

[TSH110 in reply to Rapunzel]

Won’t it just be destroyed again by antibodies? Didn’t that happen with sheep’s thyroids that were transplanted into patients in the early days of treatment in the west? I suppose it might last a decade or so, might even see me out! That’s assuming autoimmune thyroid disease is at the root of the problem, of course. I wonder if it would work as well as the original before it got nobbled or would it be a bit like taking tablets - a bit of a blunt instrument.

[helvella Administrator Thyroid UK in reply to TSH110]

I also see issues with the innervation of the thyroid. - Which seems excessive for a gland which simply sits there and responds to TSH in the blood supply! Why does it need more than the tiniest connection?