Needle‐free pneumatic injection device; histologic assessment using a rat model and parameter comparison in predicting collagen synthesis degree

Abstract

Background: Needle-free pneumatic injections have been recently introduced to the field of dermatology to inject such substances as hyaluronic acid. However, data on the influence of various pneumatic injection parameters on collagen synthesis are lacking. Objective: Compare the effect of diameter, pressure, and volume of a pneumatic injection jet on collagen synthesis and fluid dispersion pattern using a rat model. Investigate if the total work force of the injection jet is useful in predicting the degree of collagen synthesis. Materials and Methods: We injected fluid with 1 mg/ml of hyaluronic concentration to adult rats. Different injection pressures and volumes were tested using devices with nozzles of different diameters. Collagen synthesis areas were then measured, and statistical analyses were performed. Results: The area of collagen fibers increased for up to two months. The injection pressure and volume did not correlate with the degree of collagen synthesis. The nozzle diameter showed a significant after two and four weeks of injection. The total work force correlated with collagen synthesis 2, 4, and 8 weeks post-injection. (P ¼ 0.043, 0.027, and 0.000, respectively). Conclusion: Collagen formation is more prominent 2 months post-hyaluronic acid injection than after 1 month when using a needle-free pneumatic injection device. The total work force, which is affected by both the nozzle diameter and injection pressure, can be helpful in predicting the degree of collagen synthesis. Lasers Surg. Med. 51:278-285, 2019.

Electronic Pneumatic Injection‐Assisted Dermal Drug Delivery Visualized by Ex Vivo Confocal Microscopy

“…Skin structure disruption of the dermis plays an important role in long-term effects of treatments focusing on skin remodeling. It activates the wound-healing process including the remodeling phase, which consists of collagen augmentation, crosslinking, and skin contraction for at least 6 months [12,15,34]. Previous studies have related EPI-induced neocollagenesis to a beneficial long-term effect of 4-6 months in rhytids [12,35], in contrast to the shortterm effects seen after needle injection with, for example, hyaluronic acid and saline [35].…”

“…To investigate EPI parameters, skin-imitating media such as polyacrylamide gel and gelatin phantom have been used previously [10][11][12]. Moreover, EPI of ink followed by skin splitting and macroscopic evaluation, and histology imaging with hematoxylin and eosin (H&E) staining have also been used for optical imaging of EPI [10,11,[13][14][15]. Although transparent media provide a clear view of injected fluid patterns, skin phantoms are currently lacking the technical refinement to mimic the biological complexity of human skin [16].…”

Application of Hyaluronic Acid as a Biopolymer Material in Reconstruction of Interdental Papilla in Rats

“…Meanwhile, the expression of BMP-2 was also increased significantly in the sham control group compared to the control group at the same time points. This may be due to the injection itself which can also lead to tissue repair (Kim et al, 2017;Cho et al, 2019;Chun et al, 2019). WISP1 was also chosen to focus on this study, as it has multiple cellular functions that include skeletal system development, vascular repair, cellular survival, wound healing, and tooth development by being a transducer of the canonical Wnt/ β-catenin pathway (Sarkar and Sharpe, 1999;Chen et al, 2009;Liu and Millar, 2010;Kim et al, 2013;Maiese, 2014;Maeda et al, 2015;Jin et al, 2017).…”

Clinical evaluation of needle‐free electronic pneumatic hyaluronic acid injection treatment for facial atrophic acne scars: A prospective, randomized comparative trial

“…According to previous in vitro and in vivo skin study data, by producing a high-velocity air jet stream, HA particles penetrate the epidermis through a tiny entry point. [17][18][19][20][21][22] After the solution reaches the dermal layer, it spreads laterally, causing a nano-bullet subcision effect which works in combination with a dermal HA filler effect. [17][18][19][20][21][22] However, in these previous studies, not all severities and subtypes of acne scars were defined, some studies lacked objective data or fixed treatment parameters, and the sample sizes have been small.…”

“…[17][18][19][20][21][22] After the solution reaches the dermal layer, it spreads laterally, causing a nano-bullet subcision effect which works in combination with a dermal HA filler effect. [17][18][19][20][21][22] However, in these previous studies, not all severities and subtypes of acne scars were defined, some studies lacked objective data or fixed treatment parameters, and the sample sizes have been small. [13][14][15][16] The current study aimed to investigate the effects and safety of EPI-HA for facial atrophic acne scars in Asian subjects.…”