The Science

THEYA Healthcare’s Post Surgery Range is made from a unique bamboo mix fabric. Bamboo fabric has been increasingly sought by consumers and retailers due its extremely soft nature as a fabric and being a renewable resource deemed more eco-friendly than cotton. Many companies market bamboo as being antibacterial, absorbent, breathable and with a high wicking ability but there was little evidence available to support these claims.

We sought to investigate these claims, while adhering to the textile industry’s standards and obtained the results for THEYA Healthcare’s bamboo mix fabric. The fabric testing was completed in the laboratory of University College Dublin Biomedical Engineering at the School of Mechanical and Materials Engineering and by BTTG, Shirley Technologies Limited, Leeds.

THEYA Healthcare’s bamboo mix fabric was tested in comparison to 100% cotton, using two bacteria that mimic those most commonly found in SSIs, one Gram-positive (Staphylococcus Epidermis) and one Gram-negative (Pseudomonas Fluorescens). Read our exciting results below!


In the clinical setting, surgical site infections (SSIs) can occur following breast surgery and can deteriorate not only a woman’s physical condition, but also her psychological condition, potentially increasing pain, length of hospital stays, length of recovery process and delaying adjuvant treatments.

Therefore, a bra that elicited a bacteriostatic effect would be beneficial to these patients. A study completed in the National Health Service (NHS) in the UK, studied patients for a period of thirty days post breast surgery and found there to be a 10.1% rate of infection present (Tanner et al., 2011).

As per the international standard test method “AATCC TM 100: 2004 Antibacterial Finishes on Textiles” (AATCC, 2004), THEYA Healthcare’s bamboo mix fabric was tested in comparison to 100% cotton, using two bacteria that mimic those most commonly found in SSIs, one Gram-positive (Staphylococcus Epidermis) and one Gramnegative (Pseudomonas Fluorescens). NaOH + EtOH is used as a positive control, to ensure a clear anti-microbial effect for the bacteria. As expected positive controls reduced all bacteria by 100%

Gram-Positive Bacteria

THEYA Healthcare’s bamboo mix fabric demonstrated an anti-microbial effect on Gram-positive Staphylococcus Epidermis when compared to 100% cotton. Specifically, the results show a reduction of 92.7% of Staphylococcus Epidermis in the bamboo mix sample, compared to 0% reduction for 100% cotton.

Percent reduction in Staphylococcus Epidermis (gram positive bacteria)

Percent reduction in Pseudomonas Fluorescens (gram negative bacteria)

Gram-Negative Bacteria

The bamboo mix demonstrated a clear anti-microbial effect on the Gram-negative Pseudomonas Fluorescens bacterium compared to 100% cotton. The results show that the bamboo mix gives a reduction of 97.4% of Pseudomonas Fluorescens compared to 0% reduction for 100% cotton.


Absorbency/Wettability The ability of an undergarment fabric to absorb large amounts of perspiration is vital for patients undergoing treatment for breast cancer, who may be experiencing hot flushes from chemotherapy or endocrine therapy or may have hot, inflamed, irritated or broken skin secondary to radiotherapy treatment. Using the Laboratory protocol derived as per the “British Standard Method of Test for Wettability of Textile Fabrics, BS4554:1970”, THEYA Healthcare’s bamboo mix fabric demonstrated a superior absorbency/ wettability rate compared to both the 100% cotton and the Amoena Frances (90% cotton, 100% elastane).
Specifically, results show that the bamboo mix has the greatest absorbency at 0.3 seconds, compared to 0.74 seconds for 100% cotton and 0.47 seconds for the Amoena Frances (90% cotton, 100% elastane). The bamboo mix has the highest wettability of the samples tested compared to 100% cotton fabric and the competitor garment
time taken for water to wet the fabric specimen (s)

Wicking Ability

The horizontal wicking rate is responsible for sweat evaporation during activity (Raja et al, 2012). It quantitatively measures the horizontal movement of water by capillary action laterally throughout a textile material. In short, the faster a fabric can draw moisture away from the skin, the more comfortable the wearer. The test conducted used the international standard test method “AATCC TM 198:2012 – Horizontal Wicking of Textiles” (AATCC, 2012). THEYA Healthcare’s bamboo mix demonstrated an increased horizontal wicking rate compared to 100% cotton and compared to the Amoena Frances (90% cotton, 100% elastane) . Specifically, the bamboo mix horizontal wicking rate was 34.7mm/s, compared to 29.1 mm/s for 100% cotton, with the lowest rate of 15.9mm/s horizontal wicking rate for the Amoena Frances (90% cotton, 100% elastane)
horizontal wicking rate

Water Vapour Resistance

In order to assess the breathability of THEYA Healthcare's bamboo mix in comparison to 100% cotton, the fabrics were evaluated using a test that simulates the heat and moisture transfer of the human skin, ISO 11092: 1993, “Textiles – Determination of physiological properties – Measurement of thermal and water‐vapour resistance under steady‐state conditions (sweating guarded‐ hotplate test)”. The fabrics were tested in a two layer assembly as post surgery bras generally have two layers of fabric given the inclusion of a breast form pocket. Water vapour resistance (Ret) is expressed in m².Pa/W and is a measure for breathability. The lower the score the more breathable the fabric. The bamboo mix double layer yielded a mean result of 10 m².Pa/W and the 100% cotton double layer a mean of 11.5 m².Pa/W. These results mean that both fabrics are highly breathable. This excellent breathability, combined with the superior horizontal wicking rate of the bamboo mix results in an improved level of comfort for patients, in particular those suffering excessive sweating as a result of their treatments.


The pH test confirmed that the pH value of THEYA Healthcare’s bamboo mix was 7 compared to a pH of 7.5 for 100% cotton. The pH of a fabric used for apparel should be between 4-7.5 (UKAS, 2016), this aids in reducing any possible kind of irritation the fabric may have on the skin (UKAS, 2016).

In addition to our comprehensive fabric testing study, a research masters at UCD was carried out in four Dublin teaching hospitals. The results of the study carried out to investigate how post operative lingerie affected the women's experience, and which type (brand) patients wear following breast cancer surgery, had a significant impact clinically and psychosocially on participants. Our bras were compared to best in class, Anita and Amoena.