| Part ⅠQuantitative evaluation of therapeutic effect and adverse reaction of Fractional CO2 Laser for the treatment of atrophic acne scars Background and ObjectiveFractional photothermolysis creates microscopic thermal wounds within the skin, named microscopic treatment zones(MTZ). In contrast to ablative skin resurfacing, these MTZ actually is a three dimensional small volumes of thermal damage, every MTZ surroundings remain normal tissue since the density just had micro change, and epidermal recovery is fast due to short migratory paths for keratinocytes. The therapeutic effect of CO2 fractional laser treatment vary with treatment modes and energy parameters. At the same time there was reported to have a wide range of complications after CO2 fractional laser treatment, such as edema, hyperpigmentation post-inflammatory, long time of erythema, scar. Many researchers have explored new ways to reduce adverse reaction and enhance efficacy of fractional laser treatment in clinical work.At present there are many non-invasive skin detection technology in the clinical work, such as dermoscopy, skin physiological index detection instrument, Visia skin analysis imaging system which directly can be used to evaluate the condition of skin more objectively. Some of them can quantitative analysis of various skin physiological functions and skin characteristics, and doctor may develop more treatment programs based on patient skin characteristics and become easy to follow up.Eric et al. reported some cases using Focal Acne Scar Treatment for acne scars, which treating only the acne scars and leaving surrounding normal skin untreated can achieve the desired effect, and reduce adverse reactions significantly. Based on this study, the present study using half-face randomized method and non-invasive skin detection technique to quantitative evaluate the efficacy and adverse reactions of Focal Fractional Laser Treatment (FFLT) in the treatment of atrophic acne scars.MethodsA randomized, self-controlled study was performed. A total of 20 patients with atrophic facial acne scars were enrolled into this study. Treatments were randomly administered in a split-face manner. Half of each subject’s face received FFLT(FFLT side), and the other half underwent full-face fractional CO2 laser treatment resurfacing(control side), for five sessions, and the interval between each treatment was 3 months. Adverse reactions were recorded and evaluated at 1 h after the first treatment; physical parameters of the skin, including erythema index, melanin index and transepidermal water loss (TEWL) were measured and evaluated before treatment and at the 1th day,3rd day,1th,2nd week and the 1th month after the first treatment. Moreover, a Visia skin analysis imaging system was used to take photographs and evaluate skin texture before treatment and the 3rd month after each treatment. Evaluation also based on the ECCA grading scale (echelle d’evaluation clinique des cicatrices d’acne) and patient satisfaction score. Statistical analysis was carried out by paired t test, Wilcoxon paired rant test, Fisher’s exact test and repeated-measure analysis of variance.Result1. Focal Fractional Laser Treatment can improve the short-term therapeutic efficacy in the treatment of atrophic acne scars:The ECCA scores were significantly decreased in the FFLT side and the control side, and was significantly lower in the FFLT side than in the control side at 3 months after the first treatment. The improvement rate was significantly higher in the FFLT side than in the control side. The patient satisfaction score was significantly higher in the FFLT side than in the control side.2. Focal Fractional Laser Treatment can reduce the acute adverse reactions in the treatment of atrophic acne scars:Pain and edema scores were decreased significantly at the FFLT side compared with the control side at 1 hour after the treatment, however no significant difference was noted in the duration of erythema or crusting between the two sides. The erythema index was significantly lower in the FFLT side than in the control side in both scarred areas and non-scarred areas on 1 day after the treatment. Both melanin index and TE WL in the FFLT side were significantly increased in scarred areas, but decreased in non-scarred areas compared with those at the control side within 3 days after the treatment. The water content of the stratum corneum at the FFLT side was significantly lower in scarred areas, but higher in non-scarred areas compared with that at the control side between day 1 and 7 after the treatment. No significant difference was observed in the erythema index, TEWL or water content of the stratum corneum between the two sides at scarred areas or non-scarred areas from 2 weeks to 3 months after the treatment.3. The long-term therapeutic efficacy of Focal Fractional Laser Treatment in the treatment of atrophic acne scars is limited:ECCA score decreased with the increase of the treatment number, and the patient’s self satisfaction scores were gradually improved after the five treatments. Compared with before treatment, skin texture scores decreased in both sides, and were significantly lower in the FFLT side than in the control side after three treatments. Consistent with the ECCA scores, they showed Focal Fractional Laser Treatment can improve the scars with less treatment times. The spots, pores, red areas and porphyrin counts were significantly lower in the control side than in the FFLT side after three treatments.ConclusionFocal Fractional Laser Treatment can improve the short-term therapeutic efficacy and reduce the acute adverse reactions in the treatment of atrophic acne scars, through quantitative analysis we found that long-term therapy of FFLT has efficacy limitations while the full-face fractional CO2 laser treatment resurfacing can solve a variety of skin problems.Part ⅡAnimal experiment and Clinical observation on the Fractional CO2 Laser Treatment Assisted Transdermal DeliveryBackground and ObjectiveLocal drug application especially transdermal medication in the clinical treatment is very widespread. But the skin as a physical barrier, especially the outer dense cuticle, resists external substances into the body and restricts the topical drug percutaneous absorption, improving the transdermal permeation has important application value.At present, researchers have developed a lot of transdermal technology to promote the transdermal absorption, such as changing the characteristic of drugs or as a carrier of drug to promote their transdermal permeation; or directly change the structure of the skin to assist drug transdermal delivery. Recent studies have found that lasers can promote drugs to penetrate the skin with an increase in drug absorbility and penetration depth. Although traditional ablative lasers have remarkable therapeutic effect, there is a high incidence of adverse reactions such as erythema and pain. Based on the theory of fractional photothermolysis, fractional lasers can improve skin permeability of drugs with reduced photothermal damage, under a certain amount of energy density, penetrates the skin to form a real aperture, this can serve as a channel of drug penetration, enhanced transdermal delivery of drug absorption.Oni G et al. demonstrated that adipose-derived stem cells can be delivered transdermally through skin following pretreatment with an ablative laser, and need further studies to determine whether those cells are viable.Weiss et al. investigated that fibroblast injections increase collagen formation, accompanied by a concomitant increase in thickness and density of dermal collagen without an inflammatory response. Fractional ablative laser is a technique for skin remodeling and resurfacing. The aim of present study is to investigate the proliferation of fibroblast and collagen deposition in dermis by autologous fibroblast transdermal delivery with fractional ablative laser and to observe the therapeutic effect of fractional laser combined with external in the treatment medication of related diseases.Methods1. One healthy domestic piglet was selected to establish animal model. Ear skin was isolated and cultured fibroblasts. After the third generation the cells were collected. The abdomens of the piglet randomly divided into four groups:control group, fractional ablative laser group, fractional ablative laser with phosphate buffer solution (PBS) group and combination treatment of fractional ablative laser and autologous fibroblast group. Three months later, a biopsy was performed. By Hematoxylin-eosin (HE) staining, Masson staining and Real-time Quantitative polymerase chain reaction, we analyzed collagen fiber arrangement and the mRNA and protein levels of type Ⅰ collagen, type Ⅲ collagen.2. In the clinical treatment of vitiligo, androgenetic alopecia and onychomycosis, several patients were treated to observe the therapeutic effect of fractional laser combined with external medication in the treatment of related diseases.Result1. According to HE staining and Masson staining, the amount of collagen in the fractional laser group, fractional laser with PBS group and fractional laser with autologous fibroblast group were much more than in the control group, and arranged more closely; the increased amount of collagen in fractional laser with autologous fibroblast group was the highest; Real-time Quantitative polymerase chain reaction showed the same results, the collagen expression levels of type I and III collagen in the fractional laser with autologous fibroblast group were the highest.2. The therapeutic effect of fractional laser combined with external medication in the treatment of vitiligo, androgenetic alopecia, onychomycosis is satisfactory.ConclusionFractional laser treatment assisted transdermal delivery can be applied to the clinical treatment of skin diseases. |
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