Extrudates of lipophilic tetracycline complexes: A new option for periodontitis therapy

The Integration of Advanced Drug Delivery Systems into Conventional Adjuvant Therapies for Peri-Implantitis Treatment

Despite the high success rates of dental implants, peri-implantitis is currently the most common complication in dental implantology. Peri-implantitis has an inflammatory nature, it is associated with the accumulation of plaque in the peri-implant tissues, and its evolution can be progressive depending on various factors, comorbidities, and poor oral health. Prophylaxis and different treatment methods have been widely discussed in recent decades, and surgical and non-surgical techniques present both advantages and disadvantages. In this work, a literature review of different studies on the application of adjuvant treatments, such as local and systemic antibiotics and antiseptic treatments, was conducted. Positive outcomes have been found in the short (up to one year after treatment) and long term (up to ten years after treatment) with combined therapies. However, there is still a need to explore new therapies based on the use of advanced drug delivery systems for the effective treatment of peri-implantitis in the long term and without relapses. Hence, micro- and nanoparticles, implants, and injectable hydrogels, among others, should be considered in future peri-implantitis treatment with the aim of enhancing overall therapy outcomes.

A lingering mouthwash with sustained antibiotic release and biofilm eradication for periodontitis

Dental plaque biofilms are believed to be one of the principal virulence factors in periodontitis resulting in tooth loss. Traditional mouthwashes are limited due to the continuous flow of saliva and poor drug penetration ability in the biofilm. Herein, we fabricated an antibiotic delivery platform based on natural polysaccharides (chitosan and cyclodextrin) as a novel mouthwash for the topical cavity delivery of minocycline. The penetration and residence mechanisms demonstrate that the platform can prolong the residence time up to 12 h on biofilms. Furthermore, sustained release can enhance the penetration of drugs into biofilms. In vitro antibiofilm experimental results indicated that the mouthwash effectively kills bacteria and eradicate biofilms. Effective treatment in vivo was confirmed by the significantly reduced dental plaque and alleviated inflammation observed in a rat periodontitis model. In summary, this novel platform can improve antibiofilm efficiency and prevent drugs from being washed away by saliva, which may provide benefits for many oral infectious diseases.

Wnt signaling: An attractive target for periodontitis treatment

Periodontitis is the most common chronic inflammatory disease, and a leading cause of tooth loss. Characterized by resorption of alveolar process and destruction of periodontal ligaments, periodontitis can impact not only periodontal tissues but also systemic diseases, such as diabetes, cardiovascular diseases, and respiratory infections. Currently, it is a hotspot to manage destruction and gain regeneration of periodontal tissues. Increasing evidence indicates that the Wnt signaling plays an important role in homeostasis of periodontal tissues, functions of periodontal derived cells, and progression of periodontitis. Its molecule expressions were abnormal in periodontitis. As such, modulators targeting the Wnt signaling may be an adjuvant therapy for periodontitis treatment. This review elucidates the role of Wnt signaling and its molecules, with a view to develop a potential application of drugs targeting the Wnt signaling for periodontitis treatment.

Quality by design thinking in the development of long-acting injectable PLGA/PLA-based microspheres for peptide and protein drug delivery

Adopting the Quality by Design (QbD) approach in the drug development process has transformed from "nice-to-do" into a crucial and required part of the development, ensuring the quality of pharmaceutical products throughout their whole life cycles. This review is discussing the implementation of the QbD thinking into the production of long-acting injectable (LAI) PLGA/PLA-based microspheres for the therapeutic peptide and protein drug delivery. Various key elements of the QbD approaches are initially elaborated using Bydureon®, a commercial product of LAI PLGA/PLA-based microspheres, as a classical example. Subsequently, the factors influencing the release patterns and the stability of the peptide and protein drugs are discussed. This is followed by a summary of the state-of-the-art of manufacturing LAI PLGA/PLA-based microspheres and the related critical process parameters (CPPs). Finally, a landscape of generic product development of LAI PLGA/PLA-based microspheres is reviewed including some major challenges in the field.

In Vitro Evaluation of Antimicrobial Activity of Minocycline Formulations for Topical Application in Periodontal Therapy

Periodontal therapy using antimicrobials that are topically applied requires slow or controlled release devices. The in vitro antimicrobial activity of biodegradable polymer formulations that contain a new minocycline lipid complex (P-MLC) was evaluated. The new P-MLC formulations that contained 11.5% minocycline were compared with pure minocycline or an existing commercial formulation, which included determination of minimal inhibitory concentration (MIC) values against two oral bacteria and activity on six-species periodontal biofilm. Moreover, the flow of gingival crevicular fluid (GCF) was modeled up to 42 d and the obtained eluates were tested both for MIC values and inhibiting biofilm formation. In general, MICs of the P-MLC formulations were slightly increased as compared with pure minocycline. Biofilm formation was clearly inhibited by all tested formulations containing minocycline with no clear difference between them. In 3.5 d old biofilms, all formulations with 250 µg/mL minocycline decreased bacterial counts by 3 log10 and metabolic activity with no difference to pure antimicrobials. Eluates of experimental formulations showed superiority in antimicrobial activity. Eluates of one experimental formulation (P₅₀₃-MLC) still inhibited biofilm formation at 28 d, with a reduction by 1.87 log10 colony forming units (CFU) vs. the untreated control. The new experimental formulations can easily be instilled in periodontal pockets and represent alternatives in local antimicrobials, and thus warrant further testing.