Formulation and in vivo efficacy study of cetuximab decorated targeted bioadhesive nanomedicine for non-small-cell lung cancer therapy

Aim: To design, optimize and evaluate docetaxel-loaded chitosan nanoparticles with (targeted) and without (nontargeted) cetuximab conjugation for the treatment of non-small-cell lung cancer (NSCLC). Materials & methods: Risk-assessment, optimization, in vitro characterizations, stability assessments, release studies, cell-culture studies were performed along with histopathology, pharmacokinetic and anticancer efficacy studies. Results: The nanoparticles of desired particle size (152.59 ± 3.90 nm to 180.63 ± 5.21 nm) which could sustain drug release for up to 70 h, were obtained. The cell-culture studies demonstrated the superiority of the formulations over Docel™. The pharmacokinetic evaluation showed the excellent systemic bioavailability of prepared NPs. The histopathology screening revealed lesser toxicity of both the nontargeted and targeted formulations. The targeted nanoformulation significantly reduced tumor growth than the nontargeted formulation and Docel. Conclusion: These results demonstrate the therapeutic potential of the prepared nanoformulation. After proper clinical validation, it could be a promising approach for the treatment of NSCLC.

Correction to: EGFR Targeted Paclitaxel and Piperine Co-loaded Liposomes for the Treatment of Triple Negative Breast Cancer

As the authors were working on similar projects on liposomes at the same time, the 3D figures of Fig. 3 bi and Fig. 3 bii were inadvertently misplaced.

A Comparative Evaluation of Fracture Toughness of Composite Resin vs Protemp 4 for Use in Strip Crowns: An In Vitro Study

Aim

The aim of this study was to compare the fracture toughness of pedo shade packable composite resin (Z100, 3M ESPE, St. Paul, USA) vs Protemp 4 (3M ESPE, Seefeld, Germany) when used inside a strip crown to restore primary incisors.

Materials and methods

Thirty-six exfoliated noncarious human primary central and lateral incisors were randomly divided into two equal groups. The teeth were prepared to standardized dimensions to receive a strip crown. All the teeth were etched, rinsed, and dried following which bonding agent was applied and light cured. In group I, pedo shade packable composite resin (Z100, 3M ESPE, St. Paul, USA) was packed into strip crowns, placed on the prepared tooth, and light cured. In group II, the strip crowns were filled with Protemp 4 (3M ESPE, Seefeld, Germany), placed on the prepared tooth, and left to autopolymerize for 10 minutes. The strip crowns were removed, and the teeth were tested using the universal testing machine until fracture. Fracture toughness of the two groups was recorded and analyzed statistically using Student's “t” test.

Results

The mean force required to fracture strip crowns restored with Protemp 4 (416.89 ± 124.58 N) was higher when compared with pedo shade packable composite resin (338.27 ± 130.99 N). However, statistical analysis did not show a significant difference in the fracture toughness between the two groups (p = 0.074), based on Student's “t” test results.

Conclusion

The fracture toughness of teeth restored with Protemp 4 was comparable with pedo shade packable composite resin when used inside a strip crown.

Clinical significance

The use of Protemp 4 is a possible alternative to pedo shade packable composite resin in restoring the primary anterior teeth, when used inside the strip crowns. The data also showed that the fracture toughness of Protemp 4 was comparable with pedo shade packable composite resin.

How to cite this article

Vignesh KC, Kandaswamy E, Muthu MS. A Comparative Evaluation of Fracture Toughness of Composite Resin vs Protemp 4 for Use in Strip Crowns: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(1):57–60.

EGFR Targeted Paclitaxel and Piperine Co-loaded Liposomes for the Treatment of Triple Negative Breast Cancer

Triple-negative breast (TNBC) cancer that is upregulated with epidermal growth factor receptor (EGFR), and devoid of both the hormonal receptors and epidermal growth factor receptor 2 (HER 2), has led to a concept of treating TNBC with EGFR-targeted therapeutics. The combination of paclitaxel (PTX) and piperine (PIP) may improve the bioavailability of paclitaxel for cancer therapy. TPGS (vit E-PEG 1000-succinate)-coated liposomes were prepared with PTX alone or in combination with PIP, and either with (targeted) or without (non-targeted) cetuximab (CTX) conjugation. The Bradford assay indicated that 75% of CTX has been conjugated on the liposomes. The size and percent encapsulation of PTX&PIP co-loaded liposomes were found to be in the range of 204 to 218 nm and 31-73%, respectively. The drug release rate was found to be higher at pH 5.5 in comparison with release at pH 6.4 and pH 7.4. Cellular uptake and toxicity studies on MDA-MB-231 cells showed that PTX&PIP co-loaded targeted liposomes have demonstrated superior uptake and cytotoxicity than their non-targeted counterparts. The IC₅₀ values of both of the liposomal formulations were found to be significantly higher than PTX control. Indeed, combining PIP with PTX control has improved the cytotoxicity of PTX control, which proved the synergistic anticancer effect of PIP. Lyophilized liposomes showed an excellent stability profile with the size range between 189 and 210 nm. Plasma stability study revealed a slight increase in the particle size due to the adsorption of plasma proteins on the surface of liposomes. The long-term stability study also indicated that liposomes were stable at 4°C.

OXIS Classification of Interproximal Contacts of Primary Molars and Its Prevalence in Three- to Four-Year-Olds

Purpose: The purpose of this study was to investigate the prevalence of different interproximal contact areas of primary molars, as described in the OXIS classification, in a group of three- to four-year-old caries-free children. Methods: This cross-sectional study was carried out with a representative sample of 4,476 contact areas of 1,119 caries-free school children. A single calibrated examiner performed a type III examination to assess the type of contact area between primary molars, as seen from the occlusal view. The contacts were scored as O (open contact), X (point contact), I (straight contact), and S (curved contact) using OXIS classification. The prevalence of the types was expressed in the form of numbers and percentages. The findings were subjected to chi-square and McNemar's tests. Results: The most common contact type was I (75.5 percent), followed by S (15.3 percent), O (5.8 percent), and X (3.3 percent). Significant differences were obtained (P<0.001) when the inter- arch comparison was performed for all except the X type of contact. Further, 401 (35.8 percent) children had more than one type of contact in dif- ferent quadrants. Conclusions: The present study highlights the existence of four different types of interproximal contact areas, O, X, I, and S, in caries-free three- to four-year-olds.

DNA biodots based targeted theranostic nanomedicine for the imaging and treatment of non-small cell lung cancer

The light absorption and emission characteristics of DNA biodots (DNA-BD), along with biocompatibility, give them a high potential for use in various medical applications, particularly in diagnostic purpose. DNA, under high pressure and temperature, condenses to form luminescent biodots. The objective of this research is to develop DNA-biodots (BD) loaded and cetuximab conjugated targeted theranostic liposomes of etoposide for lung cancer imaging and therapy. Theranostic liposomes were prepared by using the solvent injection method and characterized for their particle size, polydispersity, zeta potential, encapsulation efficiency, and pH-dependent in-vitro release, SEM, TEM AFM, EDX, and XRD. The t₅₀% (time at which 50% of the drug releases from the preparation) of the formulations was pH-dependent, with a significant increase in the release at lower pH (5.5). To kill A549 adenocarcinoma cells, the etoposide (control) required significantly (p < 0.05) higher drug concentrations in comparison to non-targeted and; the non-targeted formulation required more concentrations in comparison to targeted liposomes. The in-vivo results demonstrated that CTX-TPGS decorated theranostic liposomes could be a promising carrier for lung theranostics due to their nano-size and selectivity towards EGFR overexpressed cells which provided an improved NSCLC targeted delivery of ETP in comparison to the non-targeted and control formulations.

Interventions with pregnant women, new mothers and other primary caregivers for preventing early childhood caries

BACKGROUND

Dental caries is one of the most common chronic diseases of childhood and is associated with adverse health and economic consequences for infants and their families. Socioeconomically disadvantaged children have a higher risk of early childhood caries (ECC).

OBJECTIVES

To assess the effects of interventions with pregnant women, new mothers or other primary caregivers of infants in the first year of life, for preventing ECC (from birth to six years of age).

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 14 January 2019), Cochrane Pregnancy and Childbirth Group's Trials Register (to 22 January 2019), Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 14 January 2019), MEDLINE Ovid (1946 to 14 January 2019), Embase Ovid (1980 to 14 January 2019) and CINAHL EBSCO (1937 to 14 January 2019). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing one or more interventions with pregnant women, mothers, or other caregivers of infants in the first year of life (intervention types included clinical, oral health education/promotion such as hygiene education, breastfeeding and other dietary advice, and policy or health service), versus standard care or placebo or another intervention. For inclusion, trials had to report at least one caries outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility, extracted data, assessed risk of bias, and assessed certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 17 RCTs (4 cluster-randomised), involving 23,732 caregivers (mainly mothers) and their children. Eleven RCTs assessed four oral health education/promotion interventions against standard care: child diet advice, child diet and feeding practice advice, breastfeeding promotion and support, and oral hygiene with child diet and feeding practice advice. Six trials assessed clinical interventions in mother's dentition, four trials chlorhexidine (CHX, a commonly prescribed antiseptic agent) or iodine-NaF application and prophylaxis versus placebo, and two trials xylitol against CHX or CHX + xylitol. At most, three trials (maximum of 1148 children and 130 mothers) contributed data to any comparison. For many trials, risk of bias was judged unclear due to lack of methodological details reported, and there was high risk of attrition bias in some trials. None of the included trials indicated receiving funding that is likely to have influenced their results. The trials were performed in high-, middle- and low-income countries. In nine trials, participants were socioeconomically disadvantaged. For child diet and feeding practice advice versus standard care, we observed a probable 15 per cent reduced risk of caries presence in primary teeth with the intervention (RR 0.85, 95% CI 0.75 to 0.97; 3 trials; 782 participants; moderate-certainty evidence), and there may be a lower mean dmfs (decayed, missing, filled primary surfaces) score (MD -0.29, 95% CI -0.58 to 0; 2 trials; 757 participants; low-certainty evidence); however, we are uncertain regarding the difference between the groups in mean dmft (decayed, missing, filled teeth) score (MD -0.90, 95% CI -1.85 to 0.05; 1 trial; 340 participants; very low-certainty evidence). For breastfeeding promotion and support versus standard care, we observed that there may be little or no a difference between groups in the risk of caries presence in primary teeth (RR 0.96, 95% CI 0.89 to 1.03; 2 trials; 1148 participants; low-certainty evidence), or mean dmft score (MD -0.12, 95% CI -0.59 to 0.36; 2 trials; 652 participants; low-certainty evidence). Dmfs was not reported for this comparison. We are uncertain whether child diet advice only compared with standard care reduces risk of caries presence in primary teeth (RR 1.08, 95% CI 0.34 to 3.37; 1 trial; 148 participants; very low-certainty evidence). Dmfs and dmft were not reported for this comparison. For oral hygiene, child diet and feeding practice advice versus standard care, we observed little or no reduced risk of caries presence in primary teeth (RR 0.91, 95% CI 0.75 to 1.10; 2 trials; 365 participants; low-certainty evidence), and are uncertain regarding difference between the groups in mean dmfs score (MD -0.99, 95% CI -2.45 to 0.47; 1 trial; 187 participants; very low-certainty evidence) and dmft score (MD -0.30, 95% CI -0.96 to 0.36; 1 trial; 187 participants; very low-certainty evidence). We observed there may be little or no difference in risk of caries presence in primary teeth between antimicrobial and placebo treatment in mother's dentition (RR 0.97, 95% CI 0.80 to 1.19; 3 trials; 479 participants; very low-certainty evidence). No trials assessing this comparison reported dmfs or dmft. For xylitol compared with CHX antimicrobial treatment, we observed there may be a lower mean dmft score with xylitol (MD -2.39; 95% CI -4.10 to -0.68; 1 trial, 113 participants; low-certainty evidence); however, we are uncertain regarding the difference between groups in caries presence in primary teeth (RR 0.62, 95% CI 0.27 to 1.39; 1 trial, 96 participants; very low-certainty evidence). Neither trial evaluating this comparison reported dmfs. No trials assessed a health policy or service intervention.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that providing advice on diet and feeding to pregnant women, mothers or other caregivers with children up to the age of one year probably leads to a slightly reduced risk of early childhood caries (ECC). The remaining evidence is low to very low certainty and is insufficient for determining which, if any, other interventions types and features may be effective for preventing ECC. Large, high-quality RCTs of oral health education/promotion, clinical, and policy and service access interventions, are warranted to determine effects and relative effects of different interventions and inform practice. We have identified 12 studies currently in progress. Those designing future studies should describe the intervention components, setting and participants, consider if and how effects are modified by intervention features and participant characteristics, and adopt a consistent approach to measuring and reporting ECC.

Antibiofilm Potential of Silver Sulfadiazine-Loaded Nanoparticle Formulations: A Study on the Effect of DNase-I on Microbial Biofilm and Wound Healing Activity

Biofilm resistance is one of the severe complications associated with chronic wound infections, which impose extreme microbial tolerance against antibiotic therapy. Interestingly, deoxyribonuclease-I (DNase-I) has been empirically proved to be efficacious in improving the antibiotic susceptibility against biofilm-associated infections. DNase-I hydrolyzes the extracellular DNA, a key component of the biofilm responsible for the cell adhesion and strength. Moreover, silver sulfadiazine, a frontline therapy in burn wound infections, exhibits delayed wound healing due to fibroblast toxicity. In this study, a chitosan gel loaded with solid lipid nanoparticles of silver sulfadiazine (SSD-SLNs) and supplemented with DNase-I has been developed to reduce the fibroblast cytotoxicity and overcome the biofilm-imposed resistance. The extensive optimization using the Box-Behnken design (BBD) resulted in the formation of SSD-SLNs with a smooth surface as confirmed by scanning electron microscopy and controlled release (83%) for up to 24 h. The compatibility between the SSD and other formulation excipients was confirmed by Fourier transform infrared, differential scanning calorimetry, and powder X-ray diffraction studies. Developed SSD-SLNs in combination with DNase-I inhibited around 96.8% of biofilm of Pseudomonas aeruginosa as compared to SSD with DNase-I (82.9%). In line with our hypothesis, SSD-SLNs were found to be less toxic (cell viability 90.3 ± 3.8% at 100 μg/mL) in comparison with SSD (Cell viability 76.9 ± 4.2%) against human dermal fibroblast cell line. Eventually, the results of the in vivo wound healing study showed complete wound healing after 21 days' treatment with SSD-SLNs along with DNase-I, whereas marketed formulations SSD and SSD-LSNs showed incomplete healing after 21 days. Data in hand suggest that the combination of SSD-SLNs with DNase-I is an effective treatment strategy against the biofilm-associated wound infections and accelerates wound healing.

Prevalence of Early Childhood Caries in India - A Systematic Review

Early Childhood Caries (ECC) is a serious public health problem in developed as well as developing nations, with high prevalence among children around the world. This systematic review of the national literature was undertaken to document the prevalence of Early Childhood Caries. Studies evaluating the prevalence of Early Childhood Caries (ECC) in the Indian population were investigated. The method under evaluation was the use of a caries experience index to calculate the prevalence of ECC. An extensive literature search was done in the following databases: PubMed, IndMED and Cochrane upto June 2016. A modified version of the Newcastle-Ottawa Scale for cross-sectional studies was used for assessment of the quality of the studies. A systematic literature search yielded 503 publications from the various databases searched. Based on the inclusion and exclusion criteria, the final number of included studies were 54. Among the included studies, 19 studies were carried out in the state of Karnataka. Analysis of all the included studies revealed the overall prevalence of ECC in India to be 49.6%. Andhra Pradesh was found to have the highest prevalence of ECC at 63%, and the lowest prevalence was reported in Sikkim (41.92%). This review has reported a high prevalence of ECC in India. None of the states reported prevalence below 40%. The government should identify ECC as a national priority which requires significant attention.

Bioadhesive micelles of d-α-tocopherol polyethylene glycol succinate 1000: Synergism of chitosan and transferrin in targeted drug delivery

The aim of this work was to prepare targeted bioadhesive d-α- tocopheryl glycol succinate 1000 (TPGS) micelles containing docetaxel (DTX) for brain targeted cancer therapy. Considering the unique bioadhesive feature of chitosan, herein, we have developed a synergistic transferrin receptor targeted bioadhesive micelles using TPGS conjugated chitosan (TPGS-chitosan), which target the overexpressed transferrin receptors of glioma cells for brain cancer therapy. The micelles were prepared by the solvent casting method and characterized for their particle size, polydispersity, zeta-potential, surface morphology, drug encapsulation efficiency, and in-vitro release. The IC₅₀ values demonstrated transferrin receptor targeted TPGS-chitosan micelles could be 248 folds more effective than Docel™ after 24h treatment with the C6 glioma cells. Further, time dependent bioadhesive cellular uptake study indicated that a synergistic effect was achieved with the chitosan and transferrin in targeted TPGS-chitosan micelles through the biodhesive property of chitosan as well as transferrin receptor mediated endocytosis. The in-vivo pharmacokinetic results demonstrated that relative bioavailability of non-targeted and targeted micelles were 2.89 and 4.08 times more effective than Docel™ after 48h of treatments, respectively.

Transition from passive to active targeting of oral insulin nanomedicines: enhancement in bioavailability and glycemic control in diabetes

Oral insulin nanomedicines are effective tools for therapy and management of both Type I and Type II diabetes. This review summarizes the various nanocarriers developed so far in the literature for oral delivery of insulin. It includes lipid-based (i.e., solid lipid nanoparticles and liposomes) and polymeric-based insulin nanomedicines (i.e., chitosan nanoparticles, alginate nanoparticles, dextran nanoparticles and nanoparticles of synthetic polymers) for sustained, controlled and targeted oral delivery of insulin. Mainly, goblet cell-targeting, vitamin B12 receptor-targeting, folate receptor-targeting and transferrin receptor-targeting aspects were focused. Currently, passive and active targeting approaches of oral insulin nanomedicines have improved the oral absorption of insulin and its bioavailability (up to 14%) that produced effective glycaemic control in in vivo models. These results indicate a promising future of oral insulin nanomedicines for the treatment of diabetes.

Effects of transferrin conjugated multi-walled carbon nanotubes in lung cancer delivery

The aim of this study was to develop multi-walled carbon nanotubes (MWCNT) which were covalently conjugated with transferrin by carbodiimide chemistry and loaded with docetaxel as a model drug for effective treatment of lung cancer in comparison with the commercial docetaxel injection (Docel™). d-Alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was used as amphiphilic surfactant to improve the aqueous dispersity and biocompatibility of MWCNT. Human lung cancer cells (A549 cells) were employed as an in-vitro model to access cellular uptake, cytotoxicity, cellular apoptosis, cell cycle analysis, and reactive oxygen species (ROS) of the docetaxel/coumarin-6 loaded MWCNT. The cellular uptake results of transferrin conjugated MWCNT showed higher efficiency in comparison with free C6. The IC50 values demonstrated that the transferrin conjugated MWCNT could be 136-fold more efficient than Docel™ after 24h treatment with the A549 cells. Flow cytometry analysis confirmed that cancerous cells appeared significantly (P<0.05) in the sub-G1 phase for transferrin conjugated MWCNT in comparison with Docel™. Results of transferrin conjugated MWCNT have showed better efficacy with safety than Docel™.

Transferrin liposomes of docetaxel for brain-targeted cancer applications: formulation and brain theranostics

Diagnosis and therapy of brain cancer was often limited due to low permeability of delivery materials across the blood-brain barrier (BBB) and their poor penetration into the brain tissue. This study explored the possibility of utilizing theranostic d-alpha-tocopheryl polyethylene glycol 1000 succinate mono-ester (TPGS) liposomes as nanocarriers for minimally invasive brain-targeted imaging and therapy (brain theranostics). The aim of this work was to formulate transferrin conjugated TPGS coated theranostic liposomes, which contain both docetaxel and quantum dots (QDs) for imaging and therapy of brain cancer. The theranostic liposomes with and without transferrin decoration were prepared and characterized for their particle size, polydispersity, morphology, drug encapsulation efficiency, in-vitro release study and brain theranostics. The particle sizes of the non-targeted and targeted theranostic liposomes were found below 200 nm. Nearly, 71% of drug encapsulation efficiency was achieved with liposomes. The drug release from transferrin conjugated theranostic liposomes was sustained for more than 72 h with 70% of drug release. The in-vivo results indicated that transferrin receptor-targeted theranostic liposomes could be a promising carrier for brain theranostics due to nano-sized delivery and its permeability which provided an improved and prolonged brain targeting of docetaxel and QDs in comparison to the non-targeted preparations.

Resveratrol loaded PLGA:d-α-tocopheryl polyethylene glycol 1000 succinate blend nanoparticles for brain cancer therapy

The systemic circulation time and biological half-life of trans-Resveratrol (RSV) is enhanced using poly(d,l-lactide-co-glycolide)–d-α-tocopheryl polyethylene glycol 1000 succinate blend nanoparticles (RSV-PLGA-BNPs).

In vivo scanning electron microscope assessment of enamel permeability in primary teeth with and without early childhood caries

BACKGROUND

Over the years, certain primary teeth have been shown to be highly sensitive to dental caries, while others have remained caries-free. It has been hypothesized that this may be attributed to differences in the permeability of the enamel surface.

AIM

The aim of the study was to evaluate the hypothesized differences in the permeability of primary tooth enamel in children with and those without Severe Early Childhood Caries (S-ECC) using scanning electron microscopy.

MATERIALS AND METHODS

Sixteen children between 3 and 6 years of age were randomly selected and divided into two groups: Group 1, children without S-ECC (n = 8), and Group 2, children with S-ECC (n = 8). In each child, 4 teeth (the maxillary right and left central and lateral incisors) were subjected to evaluation. An impression was made with polyvinylsiloxane impression material, and scanning electron microscopy was used to inspect the negative replicas for droplets.

RESULTS

The results indicated higher significance when individual regions (cervical, middle, and incisal thirds) in the two groups were evaluated and compared. Similarly, the overall results showed high statistical significance between S-ECC and non-S-ECC teeth.

CONCLUSION

There could be a positive relationship between the permeability of tooth enamel and the development of caries, which needs further research.