Patient-Reported Functional Impairment Due to Hearing Loss and Tinnitus After Cisplatin-Based Chemotherapy

Reversible opening of the blood-labyrinth barrier by low-pressure pulsed ultrasound and microbubbles for the treatment of inner ear diseases

Systemic drug administration provides convenience and non-invasive benefits for preventing and treating inner ear diseases. However, the blood-labyrinth barrier (BLB) restricts the transport of drugs to inner ear tissues. Ultrasound can stimulate specific areas and penetrate tissues, with the potential to overcome physiological barriers. We present a novel strategy based on low-pressure pulsed ultrasound assisted by microbubbles (USMB) to transiently open the BLB and deliver therapeutics into the inner ear. A pulsed ultrasound device with adjustable pressure was established; the generated ultrasound was transmitted through the external auditory canal into the guinea pig's inner ear. We observed that the application of microbubbles allowed the use of safe and efficient ultrasound conditions to penetrate the BLB. We found that USMB-mediated BLB opening seemed to be associated with a reduced expression of the tight junction proteins zonula occludens-1 and occludin. Following intravenous administration, hydrophilic dexamethasone sodium phosphate (DSP), hydrophobic curcumin (CUR), as well as drug-loaded nanoparticles (Fe3O4@CUR NPs) could be efficiently delivered into the inner ear. We observed better drug accumulation in the perilymph of the inner ear, resulting in less drug (cisplatin)-induced ototoxicity. Furthermore, physiological, hematological, and histological studies showed that the modulation of the BLB by low-pressure USMB was a safe process without significant adverse effects. We conclude that USMB could become a promising strategy for the systematic delivery of therapeutics in the treatment of inner ear diseases.

Comprehensive Audiologic Analyses After Cisplatin-Based Chemotherapy

Importance

Cisplatin is highly ototoxic but widely used. Evidence is lacking regarding cisplatin-related hearing loss (CRHL) in adult-onset cancer survivors with comprehensive audiologic assessments (eg, Words-in-Noise [WIN] tests, full-spectrum audiometry, and additional otologic measures), as well as the progression of CRHL considering comorbidities, modifiable factors associated with risk, and cumulative cisplatin dose.

Objective

To assess CRHL with comprehensive audiologic assessments, including the WIN, evaluate the longitudinal progression of CRHL, and identify factors associated with risk.

Design, Setting, and Participants

The Platinum Study is a longitudinal study of cisplatin-treated testicular cancer survivors (TCS) enrolled from 2012 to 2018 with follow-up ongoing. Longitudinal comprehensive audiologic assessments at Indiana University and Memorial Sloan Kettering Cancer Center included 100 participants without audiometrically defined profound hearing loss (HL) at baseline and at least 3.5 years from their first audiologic assessment. Data were analyzed from December 2013 to December 2022.

Exposures

Factors associated with risk included cumulative cisplatin dose, hypertension, hypercholesterolemia, diabetes, tobacco use, physical inactivity, body mass index, family history of HL, cognitive dysfunction, psychosocial symptoms, and tinnitus.

Main Outcomes and Measures

Main outcomes were audiometrically measured HL defined as combined-ears high-frequency pure-tone average (4-12 kHz) and speech-recognition in noise performance measured with WIN. Multivariable analyses evaluated factors associated with risk for WIN scores and progression of audiometrically defined HL.

Results

Median (range) age of 100 participants at evaluation was 48 (25-67) years; median (range) time since chemotherapy: 14 (4-31) years. At follow-up, 78 (78%) TCS had audiometrically defined HL; those self-reporting HL had 2-fold worse hearing than TCS without self-reported HL (48 vs 24 dB HL; P < .001). A total of 54 (54%) patients with self-reported HL showed clinically significant functional impairment on WIN testing. Poorer WIN performance was associated with hypercholesterolemia (β = 0.88; 95% CI, 0.08 to 1.69; P = .03), lower-education (F1 = 5.95; P = .004), and severity of audiometrically defined HL (β̂ = 0.07; 95% CI, 0.06 to 0.09; P < .001). CRHL progression was associated with hypercholesterolemia (β̂ = -4.38; 95% CI, -7.42 to -1.34; P = .01) and increasing age (β̂ = 0.33; 95% CI, 0.15 to 0.50; P < .001). Importantly, relative to age-matched male normative data, audiometrically defined CRHL progression significantly interacted with cumulative cisplatin dose (F1 = 5.98; P = .02); patients given 300 mg/m2 or less experienced significantly less progression, whereas greater temporal progression followed doses greater than 300 mg/m2.

Conclusions and Relevance

Follow-up of cisplatin-treated cancer survivors should include strict hypercholesterolemia control and regular audiological assessments. Risk stratification through validated instruments should include querying hearing concerns. CRHL progression relative to age-matched norms is likely associated with cumulative cisplatin dose; investigation over longer follow-up is warranted.

Inhibition of CISD1 attenuates cisplatin-induced hearing loss in mice via the PI3K and MAPK pathways

Cisplatin is an effective chemotherapeutic drug for different cancers, but it also causes severe and permanent hearing loss. Oxidative stress and mitochondrial dysfunction in cochlear hair cells (HCs) have been shown to be important in the pathogenesis of cisplatin-induced hearing loss (CIHL). CDGSH iron sulfur domain 1 (CISD1, also known as mitoNEET) plays a critical role in mitochondrial oxidative capacity and cellular bioenergetics. Targeting CISD1 may improve mitochondrial function in various diseases. However, the role of CISD1 in cisplatin-induced ototoxicity is unclear. Therefore, this study was performed to assess the role of CISD1 in cisplatin-induced ototoxicity. We found that CISD1 expression was significantly increased after cisplatin treatment in both HEI-OC1 cells and cochlear HCs. Moreover, pharmacological inhibition of CISD1 with NL-1 inhibited cell apoptosis and reduced mitochondrial reactive oxygen species accumulation in HEI-OC1 cells and cochlear explants. Inhibition of CISD1 with small interfering RNA in HEI-OC1 cells had similar protective effects. Furthermore, NL-1 protected against CIHL in adult C57 mice, as evaluated by the auditory brainstem response and immunofluorescent staining. Mechanistically, RNA sequencing revealed that NL-1 attenuated CIHL via the PI3K and MAPK pathways. Most importantly, NL-1 did not interfere with the antitumor efficacy of cisplatin. In conclusion, our study revealed that targeting CISD1 with NL-1 reduced reactive oxygen species accumulation, mitochondrial dysfunction, and apoptosis via the PI3K and MAPK pathways in HEI-OC1 cell lines and mouse cochlear explants in vitro, and it protected against CIHL in adult C57 mice. Our study suggests that CISD1 may serve as a novel target for the prevention of CIHL.

Association of hearing loss with patient-reported functional outcomes in adult survivors of childhood cancer

BACKGROUND

Hearing loss is prevalent following ototoxic therapy for childhood cancer. Associations between hearing loss, self-perceived hearing handicap, and functional outcomes have not been examined in survivors.

METHODS

Adult survivors treated with platinum or head and neck radiotherapy with hearing loss were recruited. A total of 237 survivors (median age at survey = 37.0 years [range = 30.0-45.0 years]; median = 29.1 years [range = 22.4-35.0 years] since diagnosis; median = 4.0 years [range = 2.9-7.7 years] from last audiogram to survey) completed the Hearing Handicap Inventory for Adults and questionnaires on social and emotional functioning and hearing aid use. Hearing loss severity was defined according to Chang criteria. Multivariable logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between hearing loss, hearing handicap, functional outcomes, and hearing aid use with adjustment for sex, race, age at hearing loss diagnosis, and age at survey.

RESULTS

Two-thirds of survivors had severe hearing loss, which was associated with increased likelihood of hearing handicap (mild-moderate handicap: OR = 2.72, 95% CI = 1.35 to 5.47; severe handicap: OR = 5.99, 95% CI = 2.72 to 13.18). Survivors with severe hearing handicap had an increased likelihood of social isolation (OR = 8.76, 95% CI = 3.62 to 21.20), depression (OR = 9.11, 95% CI = 3.46 to 24.02), anxiety (OR = 17.57, 95% CI = 3.77 to 81.84), reduced personal income (OR = 2.82, 95% CI = 1.46 to 5.43), and less than full-time employment (OR = 2.47, 95% CI = 1.30 to 4.70). Survivors who did not use a recommended hearing aid were twice as likely to have less than full-time employment (OR = 2.26, 95% CI = 1.10 to 4.61) and reduced personal income (OR = 2.24, 95% CI = 1.08 to 4.63) compared with survivors who wore a hearing aid.

CONCLUSION

Self-perceived hearing handicap beyond measured hearing loss is associated with reduced functional outcomes. Assessment of hearing handicap may facilitate targeted interventions in adult survivors with hearing loss.

Combined genetic polymorphisms of the GSTT1 and NRF2 genes increase susceptibility to cisplatin-induced ototoxicity: A preliminary study

OBJECTIVE

The genotype-phenotype relationship in cisplatin-induced ototoxicity remains unclear. By assessing early shifts in distortion product otoacoustic emission (DPOAE) levels after initial cisplatin administration, we aimed to discriminate patients' susceptibility to cisplatin-induced ototoxicity and elucidate their genetic background.

STUDY DESIGN

A prospective cross-sectional study.

SETTING

Tertiary referral hospital in Japan.

PATIENTS

Twenty-six patients with head and neck cancer were undergoing chemoradiotherapy with three cycles of 100 mg/m2 cisplatin.

INTERVENTIONS

Repetitive pure-tone audiometry and DPOAE measurements, and blood sampling for DNA extraction were performed. Patients were grouped into early ototoxicity presence or absence based on whether DPOAE level shifts exceeded the corresponding reference limits of the 21-day test interval.

MAIN OUTCOME MEASURES

Hearing thresholds after each cisplatin cycle, severity of other adverse events, and polymorphisms in cisplatin-induced ototoxicity-associated genes were compared.

RESULTS

Early ototoxicity was present in 14 and absent in 12 patients. Ototoxicity presence on DPOAEs was associated with greater progression of hearing loss in frequencies ≥2 kHz throughout therapy and with higher ototoxicity grades compared with ototoxicity absence. Ototoxicity was further associated with grade ≥2 nausea. Ototoxicity presence was genetically associated with the GSTT1 null genotype and G-allele of NFE2L2 rs6721961, whereas ototoxicity absence was associated with the GSTM1 null genotype. Dose-dependent progression of hearing loss was the greatest in the combined genotype pattern of GSTT1 null and the T/G or G/G variants of rs6721961.

CONCLUSION

Early DPOAE changes reflected genetic vulnerability to cisplatin-induced ototoxicity. Hereditary insufficiency of the antioxidant defense system causes severe cisplatin-induced hearing loss and nausea.

Development of a Prognostic Nomogram for Modified Tinnitus Relieving Sound Therapy for Subjective Tinnitus

OBJECTIVE

We aimed to develop a modified tinnitus-relieving sound system and establish a model for predicting its treatment effects.

STUDY DESIGN

Retrospective study.

SETTING

Tinnitus Specialist Clinic of Eye & ENT Hospital, Fudan University.

METHODS

We recruited 107 patients undergoing modified tinnitus-relieving sounds between August 2020 and May 2021. Patients were divided into training (n = 75) and validation (n = 32) cohorts in a 7:3 ratio. The treatment outcome was Tinnitus Handicapped Inventory scores. Features were established using a least absolute shrinkage and selection operator-derived logistic regression model, where the selected clinical risk factors were included in the multivariate logistic regression, and a nomogram was established based on the model. The discrimination and calibration abilities of the nomogram were evaluated using the Hosmer-Lemeshow test and calibration curves. Decision curve analysis (DCA) was used to evaluate the net benefit of predictive efficacy.

RESULTS

Multivariate logistic analysis indicated that the initial Tinnitus Handicapped Inventory score (odds ratio [OR]: 1.13 [1.07-1.19], P < .001) and treatment duration (OR: 3.4 [1.34-8.62], P < .001) were positive factors for improved tinnitus. The nomogram model that included baseline Tinnitus Handicapped Inventory score and treatment duration achieved a better concordance index of 0.880. DCA revealed that the nomogram model could lead to net benefits and exhibited a wider range of threshold probabilities for the prediction of therapeutic effects.

CONCLUSION

Our study suggests that the nomogram model, including baseline Tinnitus Handicapped Inventory score and treatment duration, could achieve optimal performance in the preoperative prediction of the therapeutic effect of modified tinnitus-relieving sound.

Association between blood volatile organic aromatic compound concentrations and hearing loss in US adults

OBJECTIVE

Benzene, ethylbenzene, meta/para-xylene, and ortho-xylene, collectively referred to as benzene, ethylbenzene, and xylene (BEX), constitute the main components of volatile organic aromatic compounds (VOACs) and can have adverse effects on human health. The relationship between exposure to BEX and hearing loss (HL) in the adult U.S. population was aimed to be assessed.

METHODS

Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) for the years 2003-2004, 2011-2012, and 2015-2016 were analyzed. This dataset included complete demographic characteristics, pure-tone audiometry measurements, and volatile organic compound detection data from the NHANES database. A weighted multivariate logistic regression model was employed to investigate the associations between blood BEX concentrations HL, low-frequency hearing loss (SFHL), and high-frequency hearing loss (HFHL).

RESULTS

2174 participants were included, with weighted prevalence rates of HL, SFHL, and HFHL being 46.81%, 25.23%, and 45.86%, respectively. Exposure to benzene, ethylbenzene, meta/para-xylene, and ortho-xylene, and cumulative BEX concentrations increased the risk of hearing loss (odds ratios [ORs] were 1.36, 1.22, 1.42, 1.23, and 1.31, respectively; all P < 0.05). In the analysis with SFHL as the outcome, ethylbenzene, m-/p-xylene, o-xylene, benzene, and overall BEX increased the risk (OR 1.26, 1.21, 1.28, 1.20, and 1.25, respectively; all P < 0.05). For HFHL, exposure to ethylbenzene, m-/p-xylene, o-xylene, benzene, and overall BEX increased the risk (OR 1.36, 1.22, 1.42, 1.22, and 1.31, respectively; all P < 0.05).

CONCLUSION

Our study indicated that a positive correlation between individual or cumulative exposure to benzene, ethylbenzene, meta/para-xylene, and ortho-xylene and the risk of HL, SFHL, and HFHL. Further research is imperative to acquire a more comprehensive understanding of the mechanisms by which organic compounds, notably BEX, in causing hearing loss and to validate these findings in longitudinal environmental studies.

Adolescent and Young Adult Germ Cell Tumors: Epidemiology, Genomics, Treatment, and Survivorship

Innovations in the care of adolescent and young adult (AYA) germ cell tumors (GCTs) are needed for one of the most common AYA cancers for which treatment has not significantly changed for several decades. Testicular GCTs (TGCTs) are the most common cancers in 15- to 39-year-old men, and ovarian GCTs (OvGCTs) are the leading gynecologic malignancies in women younger than 25 years. Excellent outcomes, even in widely metastatic disease using cisplatin-based chemotherapy, can be achieved since Einhorn and Donohue's landmark 1977 study in TGCT. However, as the severity of accompanying late effects (ototoxicity, neurotoxicity, cardiovascular disease, second malignant neoplasms, nephrotoxicity, and others) has emerged, efforts to deintensity treatment and find alternatives to cisplatin have taken on new urgency. Current innovations include the collaborative design of clinical trials that accrue GCTs across all ages and both sexes, including adolescents (previously on pediatric trials), and OvGCT (previously on gynecologic-only trials). Joint trials accrue larger sample sizes at a faster rate and therefore evaluate new approaches more rapidly. These joint trials also allow for biospecimen collection to further probe GCT etiology and underlying mechanisms of tumor growth, thus providing new therapeutic options. This AYA approach has been fostered by The Malignant Germ Cell International Consortium, which includes over 115 GCT disease experts from pediatric, gynecologic, and genitourinary oncologies in 16 countries. Trials in development incorporate, to our knowledge, for the first time, molecular risk stratification and precision oncology approaches on the basis of specific GCT biology. This collaborative AYA approach pioneering successfully in GCT could serve as a model for impactful research for other AYA cancer types.

Ototoxicity associated with high-dose carboplatin for patients with previously treated germ cell tumors

BACKGROUND

High-dose carboplatin is an essential part of curative high-dose chemotherapy (HDCT) for patients with previously treated germ cell tumors (GCTs). Although hearing loss (HL) is a known side effect of HDCT, data on its severity and characteristics are limited.

METHODS

Eligible patients received HDCT for GCTs from 1993 to 2017 and had audiograms before and after HDCT. HL severity was classified by American Speech-Language-Hearing Association criteria, and mean change in hearing threshold at each frequency (0.25-8 kHz) was estimated from pre- to post-HDCT and between HDCT cycles.

RESULTS

Of 115 patients (median age, 32 years), 102 (89%) received three cycles of HDCT. Of 106 patients with normal hearing to mild HL in the speech frequencies (0.5-4 kHz) before HDCT, 70 (66%) developed moderate to profound HL in the speech frequencies after HDCT. Twenty-five patients (22%) were recommended for hearing aids after HDCT. Patients with moderate to profound HL isolated to the higher frequencies (6-8 kHz) before HDCT were more likely to develop moderate to profound HL in the speech frequencies after HDCT (94% vs. 61%; p = .01) and to be recommended for hearing aids (39% vs. 18%; p = .05).

CONCLUSIONS

HL was frequent after HDCT for GCTs, with most patients developing at least moderate HL in the speech frequencies and approximately one in five recommended for hearing aids. Moderate to profound HL isolated to high frequencies at baseline was predictive of more clinically significant hearing impairment after HDCT.

PLAIN LANGUAGE SUMMARY

Some patients with germ cell tumors, the most common malignancy in adolescent and young adult men, are not cured with standard-dose chemotherapy and require high-dose chemotherapy (HDCT). Using detailed hearing assessments of patients receiving HDCT, we found that most patients developed significant hearing loss and that one in five needed hearing aids. Thus, strategies to reduce this side effect are urgently needed, and all patients receiving HDCT should have a hearing test after therapy.

Adverse health outcomes and global quality of life in long-term testicular cancer survivors: a longitudinal 30-year perspective

BACKGROUND

The aim of this study was to characterize the prevalence of self-reported adverse health outcomes (AHOs), track changes in AHOs, and examine their impact on health-related quality of life (HrQoL) in testicular cancer survivors (TCSs) who were diagnosed between 1980 and 1994. These assessments were conducted during two survey waves (SWs), with the first occurring ∼12 years after surgery-only or platinum-based chemotherapy (PBCT), and the second ∼28 years after initial treatment. The study primarily focused on 'typical AHOs', which included Peripheral Sensory Neuropathy (PSN), Raynaud's phenomenon, Tinnitus, and Hearing loss.

PATIENTS AND METHODS

A total of 427 TCSs were included in the evaluation, distributed as follows: surgery-only group (n = 155), PBCT-standard group with ≤850 mg cisplatin (n = 222), and PBCT-high group with >850 mg cisplatin (n = 50). For comparison of HrQoL, men from the general population served as a control group (referred to as 'Norms'). The statistical significance level was set at P < 0.05, and clinical importance, in terms of testing HrQoL differences, was defined as Δ ≥2.5 points.

RESULTS

A higher number of TCSs who underwent PBCT reported experiencing typical AHOs compared with those who had surgery only. The highest prevalence rates were observed among TCSs who had undergone PBCT-high. Further, the number of TCSs describing typical AHOs, except Raynaud's phenomenon, increased during the observation period of 16 years. At the last SW, a median of 4 AHOs (any type) were reported after PBCT-high compared with a median of 2 AHOs after Surgery-only or after PBCT-standard. With Surgery-only as reference, PBCT-high, but not PBCT-standard, was associated with decreasing physical HrQoL in the last SW (A2 Regression coefficient: -4.3; P = 0.008). When comparing all TCSs with Norms no clinically important difference in physical and mental HrQoL was observed at either SW. However, at the last SW, TCSs after PBCT-high therapy represented a subgroup of TCSs with clinically important impairment of HRQoL. Of the typical AHOs, only PSN reduced HrQoL. Chronic fatigue, pain, anxiety/depression, sexual dysfunction, unemployment, being single, and low education were additional covariates.

CONCLUSIONS

After a median of 28 years since their treatment, HrQoL in TCSs was found to be comparable to that of Norms. This similarity held true even though AHOs, especially after PBCT-high, were becoming more prevalent among TCSs. The study revealed that individuals with a history of PBCT-high are at a high risk of experiencing a significantly increased prevalence of long-term AHOs, which subsequently leads to diminished HrQoL. It is crucial to recognize and provide specialized attention to these TCSs during lifelong follow-up care.

Immune checkpoint inhibitor-related hearing loss: a systematic review and analysis of individual patient data

PURPOSE

Immune checkpoint inhibitors (ICIs) are related to various immune-related adverse events (irAEs). However, the knowledge is limited with rare irAEs like hearing loss. Therefore, we evaluated the characteristics, presentation, and treatment of ICI-related hearing loss by reviewing the individual patient data from the previous studies.

METHODS

We conducted a systematic search of the Web of Science, PubMed, and Embase databases for studies published until 17 November 2022. The selected MeSH search terms were "hearing loss" OR "hearing impairment" OR "ototoxicity" OR "vestibular toxicity" OR "audiovestibular toxicity" AND "immune checkpoint inhibitor" OR "immunotherapy."

RESULTS

A total of 38 patients were included. Melanoma was the most frequent diagnosis (73.7%). The median time from ICI initiation to hearing loss development was 3 months. The hearing impairment was secondary to bilateral sensorineural hearing loss (SNHL) in 24 (68.6%) patients, and at least one other irAE accompanied the hearing loss in 24 patients. Hearing loss significantly improved in 45.7% of the patients. The overall response rate and disease control rate were 67.6% and 85.3%, respectively.

CONCLUSION

We observed that most cases of ICI-related hearing loss were reversible, observed in patients with melanoma, accompanied by other irAEs, and associated with a high response rate to ICIs. With the expanded use of ICIs in the earlier treatment lines and adjuvant settings, the number of survivors with ICI-related hearing loss is expected to increase. Further research is needed to define the true prevalence of ICI-related hearing loss, optimal diagnosis, and management.

Intravenous N-Acetylcysteine to Prevent Cisplatin-Induced Hearing Loss in Children: A Nonrandomized Controlled Phase I Trial

PURPOSE

Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.

PATIENTS AND METHODS

In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.

RESULTS

Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021-0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011-0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.

CONCLUSIONS

NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

Gelatin-based anticancer drug delivery nanosystems: A mini review

Drug delivery nanosystems (DDnS) is widely developed recently. Gelatin is a high-potential biomaterial originated from natural resources for anticancer DDnS, which can effectively improve the utilization of anticancer drugs and reduce side effects. The hydrophilic, amphoteric behavior and sol-gel transition of gelatin can be used to fulfill various requirements of anticancer DDnS. Additionally, the high number of multifunctional groups on the surface of gelatin provides the possibility of crosslinking and further modifications. In this review, we focus on the properties of gelatin and briefly elaborate the correlation between the properties and anticancer DDnS. Furthermore, we discuss the applications of gelatin-based DDnS in various cancer treatments. Overall, we have summarized the excellent properties of gelatin and correlated with DDnS to provide a manual for the design of gelatin-based materials for DDnS.