In Vivo Test-System to Monitor Tissue Responses


Unique opportunities for animal testing using the avian model:

In vivo test-tube: the growing feather as a dermal test-site for temporal, qualitative and quantitative assessment of cellular responses to test-material


In animal testing, minimally invasive procedures that provide insight into local and systemic activities following exposure to test-material is desirable. The blood and other body fluids provide a suitable window to monitor systemic effects of test-materials. Monitoring activities of, and responses to, test-material in a complex tissue of a living organism presents a greater challenge.

The skin and its derivatives (e.g. foot-pad, foot-web, earlobe, wattle) have been used extensively to examine cellular immune responses, whereby the time of appearance, duration, type, and extent of the visual skin reaction (e.g. swelling) serve as relative measures of the immune response. Qualitative and quantitative assessment of cellular/tissue responses to test-materials occurring at the site of injection is however only possible by collecting tissue samples that can be examined post-collection. Collection of injected tissue involves invasive procedures and often requires euthanization of the experimental animal, eliminating the possibility of monitoring the course of the response from initiation to resolution in the same individual.   

In birds, the living integument includes growing feathers. University of Arkansas scientists hypothesized that the growing feather may be an excellent test-tissue. In chickens, the living portion of a growing feather is a column of approximately 8-10 mm in height with a 2-3 mm diameter. It consists mostly of inner dermis (pulp) surrounded by epidermis and an outer sheath. Micro-injection of the pulp of several growing feathers (e.g. 20/bird) with test-material [e.g. (recall)-antigens, adjuvants, immunomodulators, nanomaterials, etc.] and collection at various times post-injection (minutes, hours, days), enables monitoring of local immune activities to test-materials. Injection and collection of growing feathers are minimally invasive procedures. Moreover, concurrent sampling of injected growing feathers and blood offers unique opportunity to monitor in vivo responses to test-materials, both at the local injection-site and in the peripheral blood circulation throughout the course of the response.

Based on laboratory analysis of samples generated using this novel method, the investigators observed that responses initiated in the dermis of growing feathers parallel those in more conventional skin test-sites. As predicted, this invention has the advantage that tissue sampling of growing feathers is less invasive than taking a blood sample, the same individual can be repeatedly sampled, and each sample constitutes a defined unit of tissue that provides a rich source of cells, RNA, DNA and proteins for ex vivo analyses.

The invention has broad application as an in vivo test system (in vivo test-tube) to study, assess and monitor local cellular/tissue  responses to test-material (e.g. innate and adaptive immune responses) and to examine effects of systemically applied test-material (drugs, nutrients, immunomodulators, etc) on cellular/tissue responses initiated in the growing feather. This novel method to monitor in vivo cellular/tissue responses constitutes an important animal model for poultry as well as veterinary and biomedical research.

The University invites inquiries on this technology from research laboratories, animal health concerns, poultry researchers, pharmaceutical companies and nutrition companies. The technology is available for licensing.


Patent Information:
App Type Country Serial No. Patent No. File Date Issued Date Expire Date
Non-Provisional United States 12/467,727 8,216,551 5/18/2009 7/10/2012 12/15/2030
For Information, Contact:
Bryan Renk
Associate Director for Technology Commercialization
University of Arkansas TCO
Gisela Erf
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