Efficacy and Safety of Lyophilized Articular Cartilage Matrix as an Injectable Facial Filler

Decellularized Extracellular Matrix Scaffolds for Soft Tissue Augmentation: From Host-Scaffold Interactions to Bottlenecks in Clinical Translation

Along with a paradigm shift in looking at soft tissue fillers from space-filling to bioactive materials, decellularized extracellular matrix (DEM) fillers have gained more attention considering their superior bioactivity. However, the complex mechanisms that govern the interaction between host tissues and DEMs have been partially understood. This review first covers the mechanisms that determine immunogenicity, angiogenesis and vasculogenesis, and recellularization and remodeling after DEM implantation into host tissue, with a particular focus on related findings from filler materials. Accordingly, the review delves into the dual role of macrophages and their M1/M2 polarization paradigm to form both constructive and destructive immune responses to DEM implants. Moreover, the contribution of macrophages in angiogenesis has been elucidated, which includes but is not limited to the secretion of angiogenic growth factors and extracellular matrix (ECM) remodeling. The findings challenge the traditional view of immune cells as solely destructive entities in biomaterials and indicate their multifaceted roles in tissue regeneration. Furthermore, the review discusses how the compositional factors of DEMs, such as the presence of growth factors and matrikines, can influence angiogenesis, cell fate, and differentiation during the recellularization process. It is also shown that the biomechanical properties of DEMs, including tissue stiffness, modulate cell responses through mechanotransduction pathways, and the structural properties of DEMs, such as scaffold porosity, impact cell-cell and cell-ECM interactions. Finally, we pointed out the current clinical applications, the bottlenecks in the clinical translation of DEM biomaterials into soft tissue fillers, as well as the naïve research areas of the field.

Surgical and Regenerative Treatment Options for Empty Nose Syndrome: A Systematic Review

OBJECTIVES

Patients with empty nose syndrome typically experience paradoxical nasal congestion, nasal dryness, epistaxis, and suffocation. Conservative management is generally preferred for empty nose syndrome. However, some patients continue to experience persistent symptoms. When symptoms do not resolve, surgical options are considered. Therefore, we reviewed the surgical and regenerative treatment options for empty nose syndrome.

METHODS

PubMed, Embase, Scopus, Cochrane Register of Controlled Trials, and Google Scholar were searched from the earliest date provided in the database until December 2022. This review included studies that assessed treatment outcomes using patient symptom scores, including the Sino-Nasal Outcome Test (SNOT-20, -22, and -25) and the Empty Nose Syndrome 6-Item Questionnaire, supplemented by various clinical examinations.

RESULTS

Twenty-eight studies were analyzed. Various materials were utilized, including submucosal injectable materials, allografts/xenografts/cadaveric implants, autologous implants, and synthetic implants. The polyethylene implant was the most commonly used (23.3%), followed by autologous, homologous, or cadaveric costal cartilage (20%). The anterior-inferior lateral nasal wall was the most frequent site of administration. Most studies indicated that surgical intervention led to significant improvements in clinical outcomes, as evidenced by endoscopic exams, acoustic rhinometry, and computed tomography scans, along with patient-reported enhancements in nasal symptoms, psychological well-being, and overall health-related quality of life. However, several studies found no improvement in certain psychological-related questionnaires or saccharin transit times. The average follow-up duration was 12.0 months (range, 2.0-27.6 months). Only two studies reported postoperative adverse effects.

CONCLUSION

Several surgical options and recent tissue regeneration techniques have demonstrated efficacy in treating empty nose syndrome. However, more detailed investigations involving a larger number of participants and a randomized control study are necessary to establish a standardized treatment protocol for patients with empty nose syndrome.