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Antibiotic-resistant infections present a serious health concern worldwide. It is estimated that there are 2.8 million antibiotic-resistant infections and 35,000 deaths in the United States every year. Such microorganisms include Acinetobacter, Enterobacterioceae, Pseudomonas, Staphylococcus and Mycobacterium. Alternative treatment methods are, thus, necessary to treat such infections. Bacteriophages are viruses of bacteria. In a lytic infection, the newly formed phage particles lyse the bacterium and continue to infect other bacteria. In the early 20th century, d’Herelle, Bruynoghe and Maisin used bacterium-specific phages to treat bacterial infections. Bacteriophages are being identified, purified and developed as pharmaceutically acceptable macromolecular “drugs,” undergoing strict quality control. Phages can be applied topically or delivered by inhalation, orally or parenterally. Some of the major drug-resistant infections that are potential targets of pharmaceutically prepared phages are Pseudomonas aeruginosa, Mycobacterium tuberculosis and Acinetobacter baumannii.

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Restoration of the lost bone volume is one of the most deliberate issues in dentistry. Sustained‐release microspherical oxytocin hormone in a poloxamer hydrogel scaffold combined with a mixture of β‐tricalcium phosphate and hydroxyapatite (CP) may serve as a suitable bone graft. The aim of this study was to design and test a novel thermosensitive hydrogel graft incorporating oxytocin‐loaded poly(d, l‐lactide‐co‐glycolide) (PLGA) sustained‐release microspheres and CP. Thermosensitive poloxamer hydrogel containing CP (HCP graft) was prepared as a base and combined with hollow microspheres (HCPM) and oxytocin‐loaded microspheres (HCPOM). Eighty Wistar rats were used for testing the grafts and a control group in 8‐mm‐diameter critical‐sized calvarial defects (CSD); (n = 20). Bone healing at the 4th and 8th weeks was evaluated by histological, histomorphometric, and radiological (micro‐computed tomography [µCT]) analyses. The results were analyzed by two‐way analysis of variance (P < .05). Oxytocin‐loaded PLGA microspheres prepared by the solvent displacement method yielded a high encapsulation efficiency of 89.5% and a slow drug release. Incorporation of the microspheres into the hydrogel graft slowed the release rate down and the release completed within 32 days. HCPOM revealed the highest new bone formation (26.45% ± 6.65% and 30.76% ± 4.37% at the 4th and 8th weeks, respectively; P < .0001) while HCPM and HCP groups revealed a bone formation of around 10% (P > .05). µCT findings of HCPOM group showed the highest mean bone mineral density values (42.21 ± 5.14 and 46.94 ± 3.30 g/cm3 for the 4th and 8th weeks, respectively; P < .0027). The proposed oxytocin‐loaded sustained‐release PLGA microspheres containing thermosensitive hydrogel graft (HCPOM) provide an accelerated bone regeneration in the rat calvaria.

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Treatment of patients with bisphosphonate usage is a significant concern for oral surgeons because it interferes with jaw bone turnover and regeneration. In case of adverse effects manifesting related to bisphosphonate use, oral surgeons are usually treating and keep the patient's symptoms under control. In this study, we aimed to investigate a new treatment protocol for medication-related osteonecrosis of the jaw (MRONJ). This treatment protocol consisted of administering human parathyroid hormone (hPTH) loaded chitosan microspheres which were prepared by ionotropic gelation method or/and the prepared microspheres were suspended in a poloxamer gel. After in-vitro optimization studies, the efficacy of the chosen formulations was evaluated in-vivo studies. Zoledronic acid was administered daily to forty-eight adult female Sprague-Dawley rats, divided into four experimental groups, at a daily concentration of 0.11 mg/kg over three weeks to induce the MRONJ model. At the end of this period, maxillary left molar teeth were extracted. In the first group, the subjects received no treatment. In the negative control group, poloxamer hydrogel containing empty microspheres were immediately applied to the soft tissues surrounding the extraction socket. The treatment group-1 was treated with local injections of poloxamer hydrogel containing hPTH. The treatment group-2 was treated with a single local injection of poloxamer hydrogel containing hPTH-loaded chitosan microspheres. Both treatment groups received a total of 7 µg of hPTH at the end of the treatment protocol. Our study demonstrates successful attenuation of MRONJ through a local drug delivery system combined with hPTH, as opposed to previously attempted treatment strategies.

Photodynamic therapy facilitates the selective destruction of cancer tissue by utilizing a photosensitizer drug, the light near the absorbance wavelength of the drug, and oxygen. Methylene Blue, 5-aminolevulinic acid (the precursor of the photosensitizer, protoporphyrin IX), porphyrin, Foscan, Chlorin e6, and HPPH have been used successfully as photosensitizers in the treatment of oral verrucous hyperplasia, oral leukoplakia, oral lichen planus, and head and neck squamous cell carcinoma. “Theranostic” liposomes can deliver a contrast agent for magnetic resonance imaging and a photosensitizer for the image-guided photodynamic therapy of head and neck cancer. Liposomes incorporating photosensitizers can be targeted to cell surface markers overexpressed on cancer cells. Novel porphyrinoids have been developed in our laboratories that are highly effective as photosensitizers. Tribenzoporphyrazines encapsulated in cationic liposomes have produced IC50 values up to 50 times lower compared to the free photosensitizers. It is anticipated that targeting these drugs to cancer stem cells, using upconversion nanoparticles for the near-infrared irradiation of tumors to activate the photosensitizers, and overcoming tumor hypoxia will enhance the efficacy of photodynamic therapy of tumors accessible to light sources.

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