Different metabolism of hexose sugars and sucrose in wound fluid and in fibroblast cultures derived from granulation tissue, hypertrophic scar and keloid

Smart 3D Printed Auxetic Hydrogel Skin Wound Dressings

Wound healing is a huge challenge worldwide causing enormous financial burden on healthcare systems. Although conventional wound dressings, such as hydrogels, bandages, and foams, facilitate wound healing, they lack the ability to monitor the wound healing process. Here, hydrogel wound dressings in the form of auxetic structures were developed by a digital light processing (DLP) printer. Paper-based colorimetric sensors were incorporated with the 3D printed auxetic hydrogel skin wound patches for monitoring the wound status through detecting pH levels and glucose concentrations. The paper-based sensors are profoundly cost-effective and were found to be capable of monitoring the wound's conditions. The developed wound dressings may assist in preventing escalation of the acute wounds into chronic stages in diabetics.

Thioflavin-modified molecularly imprinted hydrogel for fluorescent-based non-enzymatic glucose detection in wound exudate

The concentration of glucose in the body's fluids is an important parameter that can indicate pathological conditions such as the progress of infected wounds. Several wearables and implantable detection approaches have been developed with high selectivity and sensitivity for glucose. However, all of them have drawbacks such as low stability, limited selectivity, and often require complex technology. In this work, we present a fluorescent-based cost-efficient imprinted hydrogel (MIH_GSH) capable of detecting glucose within 30 ​min. The imprinting approach allows us to improve the selectivity for glucose, overcoming the low specificity and limited binding efficiency at neutral pH of boronic acid-based detection mechanisms. The binding affinity determined for glucose-MIH_GSH was indeed 6-fold higher than the one determined for the non-imprinted hydrogel with a calculated imprinting factor of 1.7. The limit of detection of MIH_GSH for glucose in artificial wound exudate was calculated as 0.48 ​mM at pH 7.4 proving the suitability of the proposed approach to diagnose chronic wounds (ca. 1 ​mM). MIH_GSH was compared with a commercial colorimetric assay for the quantification of glucose in wound exudate specimens collected from hospitalized patients. The results obtained with the two methods were statistically similar confirming the robustness of our approach. Importantly, whereas with the colorimetric assay sample preparation was required to limit the interference of the sample background, the fluorescent signal of MIH_GSH was not affected even when used to measure glucose directly in bloody samples. The sensing mechanism here proposed can pave the way for the development of cost-efficient and wearable point-of-care tools capable of monitoring the glucose level in wound exudate enabling the quick assessment of chronic injuries.

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Highly sensitive and selective non-enzymatic approach to detect glucose in wound exudate.

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The fluorescent-based method ensured the detection of glucose in complex biological samples.

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The imprinting approach allowed overcoming the drawback of boronic acid-based methods.

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The cost-efficient approach is suitable for the development of point-of-care devices.

Hypertrophic scars and keloids: Overview of the evidence and practical guide for differentiating between these abnormal scars

Although hypertrophic scars and keloids both generate excessive scar tissue, keloids are characterized by their extensive growth beyond the borders of the original wound, which is not observed in hypertrophic scars. Whether or not hypertrophic scars and keloids are two sides of the same coin or in fact distinct entities remains a topic of much debate. However, proper comparison between the two ideally occurs within the same study, but this is the exception rather than the rule. For this reason, the goal of this review was to summarize and evaluate all publications in which both hypertrophic scars and keloids were studied and compared to one another within the same study. The presence of horizontal growth is the mainstay of the keloid diagnosis and remains the strongest argument in support of keloids and hypertrophic scars being distinct entities, and the histopathological distinction is less straightforward. Keloidal collagen remains the strongest keloid parameter, but dermal nodules and α-SMA immunoreactivity are not limited to hypertrophic scars alone. Ultimately, the current hypertrophic scars-keloid differences are mostly quantitative in nature rather than qualitative, and many similar abnormalities exist in both lesions. Nonetheless, the presence of similarities does not equate the absence of fundamental differences, some of which may not yet have been uncovered given how much we still have to learn about the processes involved in normal wound healing. It therefore seems pertinent to continue treating hypertrophic scars and keloids as separate entities, until such a time as new findings more decisively convinces us otherwise.

Effect of glucose concentration on the growth of normal human dermal fibroblasts in vitro

OBJECTIVE

Glucose requirements increase in tissue repair as glucose is an energy source for cell proliferation and the formation of extracellular matrix components. Glucose concentrations in leg ulcer wound fluid are lower than in normal human serum, with a median of 0.7 mM (range: 0.3-1.2 mM). This study investigated the effect of such low concentrations on the growth of fibroblasts in vitro.

METHOD

Fibroblasts from 50-year-old and 87-year-old subjects were used. Growth in medium with various concentrations of glucose was determined by a colorimetric assay and microphotography.

RESULTS

Up to day 6, there were minimal differences in growth, but after day 6 a clear dose-dependent increase in growth was observed. In the lower dose range (up to 2.3 mM), growth was highly dose-dependent (r2 = 0.981), with an increase of 1.8 mM stimulating cell growth by day 10 up to 163% of the controls (p < 0.0001). Concentrations of 5.5-25.5 mM glucose stimulated cell growth by day 10 to about 210% of the controls (p < 0.0001), with little difference between these concentrations.

CONCLUSION

These results suggest that glucose enhancement to cells involved in healing might serve as an adjunctive treatment for chronic wounds.