瘢痕疙瘩如何精准治疗？3D打印水凝胶敷料技术解析

Keloid is a pathological fibroproliferative disorder that occurs after skin trauma. Its characteristic feature is the continuous hyperplasia of scar tissue, which extends beyond the original wound boundary and invades surrounding normal skin, forming a hard, raised mass. Clinically, it is often accompanied by intractable itching and pain, and severe cases can result in ulceration [1,2]. The pathological features are characterized by persistent inflammatory responses, overexpression of growth factors, increased proliferation of fibroblasts and activation of myofibroblasts, excessive deposition of collagen and extracellular matrix, increased angiogenesis, and reduced apoptosis [3]. This condition is more prevalent in adolescents and individuals aged 20 to 30 years [1]. Currently, clinical treatments for keloids include medications, surgery, and radionuclide patch therapy, but each has certain limitations [4]. Medications have significant individual variability, numerous adverse effects with long-term use, and poor patient compliance [5].单纯的手术治疗复发率高[4]. Ferdinand W et al. [6] conducted a two-year follow-up study on 90 patients who underwent surgical excision followed by postoperative radiotherapy for keloids. The results showed an overall recurrence rate of 21%, with potential gender differences: the recurrence rate was as high as 31% in male patients and only 12% in female patients. Radionuclide patch therapy, as an adjuvant treatment, works by encapsulating radionuclides such as ³²P, ⁹⁰Sr-⁹⁰Y within a patch, which is tightly adhered to the surface of the lesion. The β-rays emitted from the decay of these radionuclides irradiate the superficial lesions at close range [7]. The physical half-life of ³²P is 14.3 days, and it emits β-rays with an energy of approximately 1.71 MeV, which have an average penetration depth of 4 mm and a maximum penetration depth of 8 mm in human tissue [8]. The physical half-life of ⁹⁰Sr is 28.5 years, and it decays into its daughter nuclide ⁹⁰Y, which has a physical half-life of 64.2 hours. ⁹⁰Y decays by emitting β-rays with an energy of 2.274 MeV, which have an average penetration depth of 2.5 mm and a maximum penetration depth of 10.3 mm in tissue [8]. When β-rays act on the lesion, they produce ionizing radiation effects, slowing the division rate of fibroblasts in the lesion and extending their cell cycle, ultimately achieving effective inhibition of abnormal tissue hyperplasia [9]. Among these, ³²P is preferred due to its moderate half-life and higher clinical availability, making it the first choice for treating most superficial lesions. Compared to ³²P, ⁹⁰Y has higher β-ray energy and deeper tissue penetration, making it suitable for treating refractory keloids [9]. Currently, the accuracy of radionuclide patch therapy dosing in clinical practice remains inadequate, largely relying on clinical experience, which can lead to complications such as radiation dermatitis, hypopigmentation or hyperpigmentation, and skin atrophy [4,10]. Additionally, traditional radionuclide patches have inherent manufacturing defects. For example, the preparation method for ³²P patches involves dropping ³²P solution onto filter paper shaped to match the lesion, then drying it for use. However, this method has two main drawbacks: uneven distribution of the radionuclide, leading to local overdosing or underdosing; and poor conformability and mechanical strength of the patch [11]. Therefore, developing conformal and uniformly distributed radiological patch materials is crucial. Hydrogels, three-dimensional porous polymer networks formed by cross-linked hydrophilic chains, have shown great potential in the field of radiological nuclide patches due to their excellent loading capacity and adjustable physicochemical properties [12]. This study used 3D scanning to obtain three-dimensional data of the lesion, directly 3D printed hydrogel patches, and conducted radiation dosimetry studies to precisely cover the lesion area and minimize damage to normal tissues, providing a new approach for precise radiotherapy of keloids.