Management of maxillofacial trauma in the elderly: A European multicenter study

BACKGROUND/AIMS

Management of maxillofacial trauma in the geriatric population poses a great challenge due to anatomical variations and medical comorbidities. The aim of this study was to analyze the management variables, timing, and outcomes of facial fractures in elderly patients (aged 70 years or more) at several European departments of oral and maxillofacial surgery.

MATERIALS AND METHODS

This study was based on a systematic computer-assisted database that allowed the recording of data from all geriatric patients with facial fractures from the involved maxillofacial surgical units across Europe between 2013 and 2017.

RESULTS

A total of 1334 patients were included in the study: 665 patients underwent closed or open surgical treatment. A significant association (P < .005) was found between the presence of concomitant injuries and a prolonged time between hospital admission and treatment. The absence of indications to treatment was associated with comorbidities and an older age (P < .000005).

CONCLUSIONS

Elderly patients require specific attention and multidisciplinary collaboration in the diagnosis and sequencing of trauma treatment. A prudent attitude may be kept in selected cases, especially when severe comorbidities are associated and function is not impaired.

The epidemiology and management of odontogenic keratocysts (OKCs): A European multicenter study

The objective of the present study was to assess the epidemiology including demographic variables, diagnostic features, and the management of odontogenic keratocyst (OKCs) at several European departments of maxillofacial and oral surgery. This study is based on a systematic computer-assisted database that allowed the recording of data from treated OKCs. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, treatment of OKCs, length of hospital stay, complications, recurrence, management and complications of eventual recurrence. A total of 405 patients, 249 male and 156 female, with 415 OKCs (407 sporadic and 8 syndromic lesions) were included in the study: 320 lesions were found in the mandible, whereas 95 were found in the maxilla. In the mandible, the most frequently involved subsite was the angle, whereas in the maxilla it was the molar region. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 204 OKCs (recurrence rate, 9%). Decompression without residual cystectomy (recurrence rate, 66%), marsupialization with residual enucleation with the use of Carnoy's solution (recurrence rate, 50%), decompression with residual cystectomy (recurrence rate, 43%), and simple enucleation (recurrence rate, 24%) were the treatment options with the highest recurrence rates. An appropriate management of odontogenic keratocysts should be individualized, taking into consideration clinical and radiological findings, as well as patients' age and comorbidities.

Cationic antimicrobial peptide NRC-03 induces oral squamous cell carcinoma cell apoptosis via CypD-mPTP axis-mediated mitochondrial oxidative stress

Pleurocidin-family cationic antimicrobial peptide NRC-03 exhibits potent and selective cytotoxicity towards cancer cells. However, the anticancer effect of NRC-03 in oral squamous cell carcinoma (OSCC) and the molecular mechanism of NRC-03 induced cancer cell death is still unclear. This study focused to investigate mitochondrial oxidative stress-mediated altered mitochondrial function involved in NRC-03-induced apoptosis of OSCC cells. NRC-03 entered the OSCC cells more easily than that of normal cells and bound to mitochondria as well as the nucleus, causing cell membrane blebbing, mitochondria swelling, and DNA fragmentation. NRC-03 induced high oxygen consumption, reactive oxygen species (ROS) release, mitochondrial dysfunction, and apoptosis in OSCC cells. Non-specific antioxidant N-acetyl-l-cysteine (NAC), or mitochondria-specific antioxidant mitoquinone (MitoQ) alleviated NRC-03-induced apoptosis and mitochondrial dysfunction indicated that NRC-03 exerts a cytotoxic effect in cancer cells via inducing cellular and mitochondrial oxidative stress. Moreover, the expression of cyclophilin D (CypD), the key component of mitochondrial permeability transition pore (mPTP), was upregulated in NRC-03-treated cancer cells. Blockade of CypD by siRNA-mediated depletion or pharmacological inhibitor cyclosporine A (CsA) significantly suppressed NRC-03-induced mitochondrial oxidative stress, mitochondrial dysfunction, and apoptosis. NRC-03 also activated MAPK/ERK and NF-κB pathways. Importantly, intratumoral administration of NRC-03 inhibited the growth of CAL-27 cells-derived tumors on xenografted animal models. Taken together, our study indicates that NRC-03 induces apoptosis in OSCC cells via the CypD-mPTP axis mediated mitochondrial oxidative stress.

Is There Enough Evidence to Regularly Apply Bone Screws for Intermaxillary Fixation in Mandibular Fractures?

PURPOSE

Intermaxillary fixation (IMF) is traditionally achieved with arch bars; however, this method has several well-known disadvantages and other techniques, such as bone screws, are available. This study evaluated current evidence regarding these IMF screws (IMFSs) for mandibular trauma and to assess whether this allows a change of treatment protocol for IMF.

MATERIALS AND METHODS

A systematic electronic literature search was conducted in the PubMed, Embase, and Cochrane databases. Titles and abstracts retrieved from the search were screened and evaluated for inclusion and exclusion criteria. The full text of all relevant articles was read and citation lists were checked for any missing references. All randomized controlled trials (RCTs) were subjected to a quality assessment. Included articles were checked for outcome measurements concerning occlusion, operative time, oral hygiene, root trauma, wire-stick injuries, and mucosa overgrowth.

RESULTS

Twenty-two articles (17 case series, 4 RCTs, and 1 cohort study) were included. None of the RCTs scored high methodologic results in the quality assessment. The results suggest IMFSs have similar malocclusion rates as arch bars, fewer wire-stick injuries, improved oral hygiene, and shorter operative time. Root damage is less likely to occur with self-drilling screws and seldom requires treatment.

CONCLUSIONS

Although the methodologic quality of the included studies is poor, self-drilling IMFSs are recommended for temporary per-operative IMF of noncomminuted mandibular fractures. More high-quality studies are required to allow an evidence-based change of protocol.

Histatin 1 enhanced the speed and quality of wound healing through regulating the behaviour of fibroblast

Objectives

Histatin 1(Hst 1) has been proved to promote wound healing. However, there was no specific study on the regulation made by Hst 1 of fibroblasts in the process of wound healing. This research comprehensively studied the regulation of Hst 1 on the function of fibroblasts in the process of wound healing and preliminary mechanism about it.

Materials and methods

The full‐thickness skin wound model was made on the back of C57/BL6 mice. The wound healing, collagen deposition and fibroblast distribution were detected on days 3, 5 and 7 after injury. Fibroblast was cultured in vitro and stimulated with Hst 1, and then, their biological characteristics and functions were detected.

Results

Histatin 1 can effectively promote wound healing, improve collagen deposition during and after healing and increase the number and function of fibroblasts. After healing, the mechanical properties of the skin also improved. In vitro, the migration ability of fibroblasts stimulated by Hst 1 was significantly improved, and the fibroblasts transformed more into myofibroblasts, which improved the function of contraction and collagen secretion. In fibroblasts, mTOR signalling pathway can be activated by Hst 1.

Conclusions

Histatin 1 can accelerate wound healing and improve the mechanical properties of healed skin by promoting the function of fibroblasts. The intermolecular mechanisms need to be further studied, and this study provides a direction about mTOR signalling pathway.

Inferior alveolar nerve injuries associated with mandibular fractures at risk: a two-center retrospective study

The aim of the study was to investigate the incidence of the inferior alveolar nerve (IAN) injury in mandibular fractures. This study is based on two databases that have continuously recorded patients hospitalized with maxillofacial fractures in two departments-Department of Maxillofacial Surgery, Vrije Universiteit University Medical Center, Amsterdam, the Netherlands, and Division of Maxillofacial Surgery, San Giovanni Battista Hospital, Turin, Italy. Demographic, anatomic, and etiology variables were considered for each patient and statistically assessed in relation to the neurosensory IAN impairment. Statistically significant associations were found between IAN injury and fracture displacement (p = 0.03), isolated mandibular fractures (p = 0.01), and angle fractures (p = 0.004). A statistically significant association was also found between IAN injury and assaults (p = 0.03). Displaced isolated mandibular angle fractures could be considered at risk for increased incidence of IAN injury. Assaults seem to be the most important etiological factor that is responsible for IAN lesions.

The accuracy of ultrashort echo time MRI sequences for medical additive manufacturing

OBJECTIVES

Additively manufactured bone models, implants and drill guides are becoming increasingly popular amongst maxillofacial surgeons and dentists. To date, such constructs are commonly manufactured using CT technology that induces ionizing radiation. Recently, ultrashort echo time (UTE) MRI sequences have been developed that allow radiation-free imaging of facial bones. The aim of the present study was to assess the feasibility of UTE MRI sequences for medical additive manufacturing (AM).

METHODS

Three morphologically different dry human mandibles were scanned using a CT and MRI scanner. Additionally, optical scans of all three mandibles were made to acquire a "gold standard". All CT and MRI scans were converted into Standard Tessellation Language (STL) models and geometrically compared with the gold standard. To quantify the accuracy of the AM process, the CT, MRI and gold-standard STL models of one of the mandibles were additively manufactured, optically scanned and compared with the original gold-standard STL model.

RESULTS

Geometric differences between all three CT-derived STL models and the gold standard were <1.0 mm. All three MRI-derived STL models generally presented deviations <1.5 mm in the symphyseal and mandibular area. The AM process introduced minor deviations of <0.5 mm.

CONCLUSIONS

This study demonstrates that MRI using UTE sequences is a feasible alternative to CT in generating STL models of the mandible and would therefore be suitable for surgical planning and AM. Further in vivo studies are necessary to assess the usability of UTE MRI sequences in clinical settings.

3D Orbital Reconstruction in a Patient with Microphthalmos and a Large Orbital Cyst-A Case Report

BACKGROUND

Orbital cysts are rare developmental anomalies that can occur in microphthalmic and anophthalmic patients. Such cysts can promote orbital growth and subsequently markedly increase the size of the orbit, which is commonly underdeveloped in these patients. Cyst removal is therefore generally dissuaded (at least) in the first 5 years.

CLINICAL CASE

A 6-year-old boy with a microphthalmos and a cyst developed protrusion of his prosthetic eye and a swelling of the lower eyelid. MRI showed a large cyst causing distortion of the right orbit. Due to the expansive orbital growth and subsequent misfitting of the prosthesis, cystectomy and orbital floor reconstruction was performed using 3D technology.

CONCLUSION

3D imaging and printing enables exact delineation of orbital cysts and the adjacent bony structures. Furthermore it offers the possibility to plan an individual surgical approach and to design and fabricate a custom fit orbital floor implant.

Controversies in ameloblastoma management: evaluation of decision making, based on a retrospective analysis

BACKGROUND

The ameloblastoma management is still challenging to the high recurrence rates and significant morbidity associated with radical treatment. The purpose of this 10-year retrospective study was to analyze the influence of ameloblastoma type and treatment strategy on the long-term outcomes and recurrence rates.

MATERIAL AND METHODS

The retrospective analyses of 64 histologically-confirmed ameloblastoma cases was performed. The possible risk factors for recurrence and the development of complications were estimated statistically.

RESULTS

The treatment strategy applied for this group of patients was the following: thirty-four patients (53.1%) were treated conservatively with enucleation or extended bone curettage. Radical treatment (bone resection) was applied in 30 (46.9%) cases. The follow-up period ranged from 2 to 10 years (mean value 4.28 ± 3,26). General recurrence rate consisted 32.8%. This study did not find significant correlations between clinical or histopathological features of the ameloblastoma and the recurrence rate. The only factor that significantly influence recurrence rate was the treatment strategy (41% in conservative treatment vs 15% in radical treatment, p<0.05). Postoperative complications were observed in 42 patients (65.6%) and included face asymmetry and disfigurement (17.2%), temporary paresthesia of the inferior alveolar nerve (IAN) - 23.4%, permanent paresthesia of IAN - 20.3%, paresis of a marginal branch of the facial nerve - 6.3%, infection 12.5%, and swelling - 20.3%. The complication rates, esthetic and functional deficiency were significantly higher in radically treated patients (p<0.05) Conclusions: Our study confirms that higher recurrence rate is associated with conservative treatment for ameloblastoma, while radical treatment leads to an increased number of postoperative complications that affect the patient's quality of life.

A population-based study of the epidemiology of oral squamous cell carcinoma in the Netherlands 1989-2018, with emphasis on young adults

There has been an increasing trend in oral squamous cell carcinoma (OSCC) in patients under 45 years of age. The aim of this study was to evaluate the burden of OSCC in the Netherlands between 1989 and 2018 among young adults (age 20-34 years) when compared to adults (age 35-44 years), and to describe the burden in older groups as well, utilizing cancer registry data to characterize incidence patterns by age, sex, and risk factors. A total of 18,963 cases of OSCC were reported. The overall incidence rate, as measured by annual percentage change (APC), increased significantly from 1989 to 2010 by 1.3% per year (95% confidence interval (CI) 0.9-1.7%) but decreased thereafter by -0.9% (95% CI -2.5% to 0.7%). Annual incidence increased significantly by 2.4% (95% CI 1.1-3.8%) for patients aged 20-34 years, while it decreased for those aged 35-44 years by -0.9% (95% CI -1.7% to 0.0%). In patients older than 60 years, incidence rates increased overall (60-74 years: APC 1.8%, 95% CI 1.5-2.1%; ≥75 years: APC 1.5%, 95% CI 1.2-1.9%). Overall, 66.5% of patients were smokers and 65.3% were alcohol consumers. The marked differences in incidence within the young age subgroups warrants further investigation to elucidate any likely disparity in biological process and clinical outcomes in these populations.

The epidemiology and management of ameloblastomas: A European multicenter study

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence. A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05). Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.

Incidence of symptomatic venous thromboembolism in oncological oral and maxillofacial operations: retrospective analysis

We retrospectively analysed the incidence of symptomatic venous thromboembolism (VTE) and associated risk factors in operations under general anaesthesia for cancer of the oral cavity. To identify symptoms related to deep venous thrombosis (DVT) and pulmonary embolism (PE), together with associated risk factors, we reviewed medical records of patients operated on in the department of oral and maxillofacial surgery at the Queen Elizabeth Hospital, Birmingham, United Kingdom, between June 2007 and October 2012. All patients were categorised according to their level of risk of VTE. The incidence of VTE was calculated with univariate associations and odds ratios with related 95% confidence intervals, where possible. In total, 233 patients were included, comprising 244 operations (mean (SD) age at operation 60.9 (13) years). Almost all patients (97%) were classified as having the highest risk of VTE. Swelling of an extremity, expectoration of blood, and tightness of the chest were the most common symptoms for suspected cases. An incidence of 0.41% was found for symptomatic VTE; one man developed a PE 2 days after operation. Associations between the analysed factors and symptomatic VTE were not significant. The development of the complication in oncological oral and maxillofacial operations seems to be rare, even in patients with a high risk. We cannot recommend the use of routine thromboprophylaxis, but it could be advocated in patients with obvious serious risk factors.

Incidence and types of complications after ablative oral cancer surgery with primary microvascular free flap reconstruction

Background

The aims of the study were 1) to evaluate the incidence and types of postoperative complications after ablative oral cancer surgery with primary free flap reconstruction and 2) identify prognostic variables for postoperative complications.

Material and Methods

Desired data was retrieved from a computer database at the department of Oral and Maxillofacial Department, Queen Elisabeth hospital Birmingham, United Kingdom, between June 2007 and October 2012. Logistic regression was used to study relationships between preoperative variables and postoperative outcomes.

Results

The study population consisted 184 patients, comprising 189 composite resections with reconstruction. Complications developed in 40.2% of the patients. Three patients (1.6%) died, 11.1% returned to the operating room, 5.3% developed donor site complications and 6.9% flap complications of which 3.2% total flap failure. In the multivariable analysis systemic complications were associated with anaesthesia time and hospital stay with red cell transfusion.

Conclusions

A significant proportion of the patients with primary free flap reconstructions after oral cancer surgery develops postoperative complications. Prolonged anaesthesia time and red cell transfusion are possible predictors for systemic complications and hospital stay respectively. Preoperative screening for risk factors is advocated for patient selection and to have realistic information and expectations.

Key words:Free flap, complications, oral cancer, risk factors, reconstruction.

Comparison of multiple against single pain intensity measurements in complex regional pain syndrome type I: analysis of 54 patients

OBJECTIVE

To describe the comparison of multiple and single pain ratings in patients with complex regional pain syndrome type I (CRPS I).

DESIGN

Correlation, agreement, and reliability analyses were performed between the average pain intensity measured 3 times a day over a course of 4 days and one single pain rating (designated the "recalled average" pain, as assessed by the patient) before treatment and at 1-, 3-, and 6-month periods after treatment.

PATIENTS

The patient population consisted of 54 patients with CRPS I in a randomized trial.

RESULTS

The results show that both measurements correlate and have excellent agreement. Furthermore, both ratings measure significant pain reduction after treatment; "recalled average" pain, however, reflects greater change in pain intensity.

CONCLUSIONS

In patients with CRPS I a single pain rating is an accurate predictor of the average pain measured by a multiple pain-rating test. Moreover, both assessments are accurate enough to determine changes in pain over time with an effective treatment.

Dental and periodontal disease in patients with inflammatory bowel disease

Objectives

Although bowel symptoms are often predominant, inflammatory bowel disease (IBD) patients can have several oral manifestations. The aim of this study was to investigate the prevalence of dental caries and periodontal disease in patients with Crohn’s disease (CD) and ulcerative colitis (UC) compared to an age and gender-matched control group of patients without IBD.

Material and methods

The DMFT (Decayed, Missing, Filled Teeth) scores and the DPSI (Dutch Periodontal Screening Index) of 229 IBD patients were retrieved from the electronic health record patient database axiUm at the Academic Centre for Dentistry Amsterdam (ACTA) and were compared to the DMFT scores and DPSI from age and gender-matched non-IBD patients from the same database.

Results

The total DMFT index was significantly higher in the IBD group compared to the control group. When CD and UC were analyzed separately, a statistically significant increased DMFT index was observed in CD patients but not in UC patients. The DPSI did not differ significantly between the IBD and non-IBD groups for each of the sextants. However, in every sextant, IBD patients were more frequently edentulous compared to the control patients.

Conclusion

CD patients have significantly more dental health problems compared to a control group. Periodontal disease did not differ significantly between IBD and non-IBD groups as determined by the DPSI.

Clinical relevance

It is important that IBD patients and physicians are instructed about the correlation between their disease and oral health problems. Strict oral hygiene and preventive dental care such as more frequent checkups should be emphasized by dental clinicians.

A review on the application of deep learning for CT reconstruction, bone segmentation and surgical planning in oral and maxillofacial surgery

Computer-assisted surgery (CAS) allows clinicians to personalize treatments and surgical interventions and has therefore become an increasingly popular treatment modality in maxillofacial surgery. The current maxillofacial CAS consists of three main steps: (1) CT image reconstruction, (2) bone segmentation, and (3) surgical planning. However, each of these three steps can introduce errors that can heavily affect the treatment outcome. As a consequence, tedious and time-consuming manual post-processing is often necessary to ensure that each step is performed adequately. One way to overcome this issue is by developing and implementing neural networks (NNs) within the maxillofacial CAS workflow. These learning algorithms can be trained to perform specific tasks without the need for explicitly defined rules. In recent years, an extremely large number of novel NN approaches have been proposed for a wide variety of applications, which makes it a difficult task to keep up with all relevant developments. This study therefore aimed to summarize and review all relevant NN approaches applied for CT image reconstruction, bone segmentation, and surgical planning. After full text screening, 76 publications were identified: 32 focusing on CT image reconstruction, 33 focusing on bone segmentation and 11 focusing on surgical planning. Generally, convolutional NNs were most widely used in the identified studies, although the multilayer perceptron was most commonly applied in surgical planning tasks. Moreover, the drawbacks of current approaches and promising research avenues are discussed.

Association of low skeletal muscle mass and systemic inflammation with surgical complications and survival after microvascular flap reconstruction in patients with head and neck cancer

BACKGROUND

Skeletal muscle mass (SMM) and chronic inflammation are associated with postoperative complications and survival.

METHODS

Patients with head and neck cancer (HNC) undergoing microvascular free flap reconstruction were included. SMM and neutrophil-to-lymphocyte ratio (NLR) were measured and their association with treatment outcomes analyzed.

RESULTS

Five hundred and fifty-four patients were included. Predictors for complications were elevated NLR in all flaps (OR 1.5), low SMM in radial forearm flap (OR 2.0), and elevated NLR combined with low SMM in fibula flap surgery (OR 4.3). Patients with solely elevated NLR were at risk for flap-related complications (OR 3.0), severe complications (OR 2.2), and when combined with low SMM for increased length of hospital stays (LOS) (+3.9 days). In early-stage HNC, low SMM (HR 2.3), and combined elevated NLR with low SMM (HR 2.6) were prognostics for decreased overall survival.

CONCLUSIONS

SMM and NLR are predictive for poor outcomes in patients with HNC undergoing microvascular reconstruction.

A Novel Treatment Concept for Advanced Stage Mandibular Osteoradionecrosis Combining Isodose Curve Visualization and Nerve Preservation: A Prospective Pilot Study

Background

Osteoradionecrosis (ORN) of the mandible is a severe complication of radiation therapy in head and neck cancer patients. Treatment of advanced stage mandibular osteoradionecrosis may consist of segmental resection and osseous reconstruction, often sacrificing the inferior alveolar nerve (IAN). New computer-assisted surgery (CAS) techniques can be used for guided IAN preservation and 3D radiotherapy isodose curve visualization for patient specific mandibular resection margins. This study introduces a novel treatment concept combining these CAS techniques for treatment of advanced stage ORN.

Methods

Our advanced stage ORN treatment concept includes consecutively: 1) determination of the mandibular resection margins using a 3D 50 Gy isodose curve visualization, 2) segmental mandibular resection with preservation of the IAN with a two-step cutting guide, and 3) 3D planned mandibular reconstruction using a hand-bent patient specific reconstruction plate. Postoperative accuracy of the mandibular reconstruction was evaluated using a guideline. Objective and subjective IAN sensory function was tested for a period of 12 months postoperatively.

Results

Five patients with advanced stage ORN were treated with our ORN treatment concept using the fibula free flap. A total of seven IANs were salvaged in two men and three women. No complications occurred and all reconstructions healed properly. Neither non-union nor recurrence of ORN was observed. Sensory function of all IANs recovered after resection up to 100 percent, including the patients with a pathologic fracture due to ORN. The accuracy evaluation showed angle deviations limited to 3.78 degrees. Two deviations of 6.42° and 7.47° were found. After an average of 11,6 months all patients received dental implants to complete oral rehabilitation.

Conclusions

Our novel ORN treatment concept shows promising results for implementation of 3D radiotherapy isodose curve visualization and IAN preservation. Sensory function of all IANs recovered after segmental mandibular resection.

A Novel Approach on Drug Delivery: Investigation of A New Nano-Formulation of Liposomal Doxorubicin and Biological Evaluation of Entrapped Doxorubicin on Various Osteosarcoma Cell Lines

OBJECTIVE

In this study we prepared a novel formulation of liposomal doxorubicin (L- DOX). The drug dose was optimized by analyses of cellular uptake and cell viability of osteosarcoma (OS) cell lines upon exposure to nanoliposomes that contained varying DOX concentrations. We intended to reduce the cytotoxicity of DOX and improve characteristics of the nanosystems.

MATERIALS AND METHODS

In this experimental study, we prepared liposomes by the pH gradient hydration method. Various characterization tests that included dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM) imaging, and UV- Vis spectrophotometry were employed to evaluate the quality of the nanocarriers. In addition, the CyQUANT® assay and fluorescence microscope imaging were used on various OS cell lines (MG-63, U2-OS, SaOS-2, SaOS-LM7) and Human primary osteoblasts cells, as novel methods to determine cell viability and in vitro transfection efficacy.

RESULTS

We observed an entrapment efficiency of 84% for DOX within the optimized liposomal formulation (L-DOX) that had a liposomal diameter of 96 nm. Less than 37% of DOX released after 48 hours and L-DOX could be stored stably for 14 days. L-DOX increased DOX toxicity by 1.8-4.6 times for the OS cell lines and only 1.3 times for Human primary osteoblasts cells compared to free DOX, which confirmed a higher sensitivity of the OS cell lines versus Human primary osteoblasts cells for L-DOX. We deduced that L- DOX passed more freely through the cell membrane compared to free DOX.

CONCLUSION

We successfully synthesized a stealth L-DOX that contained natural phospholipid by the pH gradient method, which could encapsulate DOX with 84% efficiency. The resulting nanoparticles were round, with a suitable particle size, and stable for 14 days. These nanoparticles allowed for adequately controlled DOX release, increased cell permeability compared to free DOX, and increased tumor cell death. L-DOX provided a novel, more effective therapy for OS treatment.